1. 1p36 deletion syndrome
2. 1q21.1 deletion syndrome
3. 1q21.1 duplication syndrome
4. 13q deletion syndrome
5. 17q21.31 microdeletion syndrome
6. 22q11.2 distal deletion syndrome
7. 22q11.2 duplication syndrome
8. 22q13 deletion syndrome
9. 2p15-16.1 microdeletion syndrome
10. 2q37 deletion syndrome
11. 3-M syndrome
12. 3C syndrome
13. 3q29 microdeletion syndrome
14. 49,XXXXY
15. 4D syndrome
16. 8p23.1 duplication syndrome
17. 9q34 deletion syndrome

1. Aagenaes syndrome
2. Aarskog–Scott syndrome
3. Aase syndrome
4. Abandoned child syndrome
5. ABCD syndrome
6. Abdallat–Davis–Farrage syndrome
7. Abderhalden–Kaufmann–Lignac syndrome
8. Abdominal compartment syndrome
9. Ablepharon macrostomia syndrome
10. Abruzzo–Erickson syndrome
11. Achard syndrome
12. Achard–Thiers syndrome
13. Ackerman syndrome
14. Acorea, microphthalmia and cataract syndrome
15. Acrocallosal syndrome
16. Acropectoral syndrome
17. Acro–dermato–ungual–lacrimal–tooth syndrome
18. Activation syndrome
19. Acute aortic syndrome
20. Acute brain syndrome
21. Acute chest syndrome
22. Acute coronary syndrome
23. Acute HME syndrome
24. Acute interstitial pneumonitis
25. Acute motor axonal neuropathy
26. Acute radiation syndrome
27. Acute respiratory distress syndrome
28. Acute retroviral syndrome
29. Adams–Nance syndrome
30. Adams–Oliver syndrome
31. Adams–Stokes syndrome
32. Adducted thumb syndrome
33. Adie syndrome
34. Adiposogenital dystrophy
35. Adult-onset immunodeficiency syndrome
36. Advanced sleep phase disorder
37. Aerotoxic syndrome
38. Afferent loop syndrome
39. Aicardi syndrome
40. Aicardi–Goutières syndrome
41. AIDS dysmorphic syndrome
42. Al-Raqad syndrome
43. Alagille syndrome
44. Albinism–deafness syndrome
45. Alcohol withdrawal syndrome
46. Alezzandrini syndrome
47. Alice in Wonderland syndrome
48. Alien hand syndrome
49. Allan–Herndon–Dudley syndrome
50. Allopurinol hypersensitivity syndrome
51. Alopecia contractures dwarfism mental retardation syndrome
52. Alpha-thalassemia mental retardation syndrome
53. Alport syndrome
54. Alström syndrome
55. Alvarez' syndrome
56. Amniotic band constriction
57. Amotivational syndrome
58. Amplified musculoskeletal pain syndromes
59. Andermann syndrome
60. Andersen–Tawil syndrome
61. Androgen insensitivity syndrome
62. Angelman syndrome
63. ANOTHER syndrome
64. Anterior cerebral artery syndrome
65. Anterior compartment syndrome
66. Anterior cutaneous nerve entrapment syndrome
67. Anterior interosseous syndrome
68. Anterior spinal artery syndrome
69. Anticonvulsant hypersensitivity syndrome
70. Antidepressant discontinuation syndrome
71. Antiphospholipid syndrome
72. Antisynthetase syndrome
73. Antley–Bixler syndrome
74. Anton–Babinski syndrome
75. Aortic arch syndrome
76. Aortocaval compression syndrome
77. Apert syndrome
78. Apparent mineralocorticoid excess syndrome
79. Arakawa's syndrome II
80. Ardalan–Shoja–Kiuru syndrome
81. AREDYLD syndrome
82. Aromatase excess syndrome
83. Arterial tortuosity syndrome
84. Arthrogryposis–renal dysfunction–cholestasis syndrome
85. Arts syndrome
86. Ascher's syndrome
87. Asherman's syndrome
88. Asperger syndrome
89. Asymmetric crying facies
90. Ataxia-pancytopenia syndrome
91. Ataxia-telangiectasia
92. Athletic heart syndrome
93. Athymhormic syndrome
94. ATR-16 syndrome
95. Atrophodermia vermiculata
96. Atypical hemolytic uremic syndrome
97. Austrian syndrome
98. Autoimmune disease
99. Autoimmune lymphoproliferative syndrome
100. Autoimmune polyendocrine syndrome type 1
101. Autoimmune polyendocrine syndrome type 2
102. Autoimmune polyendocrine syndrome type 3
103. Autoimmune polyendocrine syndrome
104. Autoinflammatory syndromes
105. Avellis syndrome
106. Axenfeld syndrome
107. Axial spondyloarthritis
108. Ayazi syndrome

1. Babinski–Nageotte syndrome
2. Baboon syndrome
3. Baggio–Yoshinari syndrome
4. Baller–Gerold syndrome
5. Bamforth–Lazarus syndrome
6. Bangstad syndrome
7. Bannayan–Riley–Ruvalcaba syndrome
8. Banti's syndrome
9. Barakat syndrome
10. Barakat-Perenthaler syndrome
11. Bardet–Biedl syndrome
12. Bare lymphocyte syndrome type II
13. Bare lymphocyte syndrome
14. Barlow's syndrome
15. Barraquer–Simons syndrome
16. Bart syndrome
17. Bartter syndrome
18. Bart–Pumphrey syndrome
19. Bassen-Kornzweig syndrome
20. Battered person syndrome
21. Bazex–Dupré–Christol syndrome
22. Beare–Stevenson cutis gyrata syndrome
23. Beckwith–Wiedemann syndrome
24. Behcet's syndrome
25. Behr syndrome
26. Benedikt syndrome
27. Benign fasciculation syndrome
28. Benjamin syndrome
29. Benzodiazepine withdrawal syndrome
30. Berdon syndrome
31. Berk–Tabatznik syndrome
32. Bernard–Soulier syndrome
33. Berserk llama syndrome
34. Bhaskar–Jagannathan syndrome
35. Biemond syndrome
36. Bilious vomiting syndrome
37. Binder's syndrome
38. Bing–Neel syndrome
39. Birt–Hogg–Dubé syndrome
40. Björnstad syndrome
41. Bland-White-Garland syndrome
42. Blau syndrome
43. Blepharophimosis, ptosis, epicanthus inversus syndrome
44. Blind loop syndrome
45. Bloom syndrome
46. Blount's disease
47. Blue baby syndrome
48. Blue diaper syndrome
49. Blue rubber bleb nevus syndrome
50. Blue toe syndrome
51. Bobble-head doll syndrome
52. Body fat redistribution syndrome
53. Boerhaave syndrome
54. Bogart–Bacall syndrome
55. Bohring–Opitz syndrome
56. Bonnet–Dechaume–Blanc syndrome
57. Bowen–Conradi syndrome
58. Brachycephalic airway obstructive syndrome
59. Brainstem stroke syndrome
60. Branchio-oculo-facial syndrome
61. Branchio-oto-renal syndrome
62. Bromism
63. Brown's syndrome
64. Brown-Séquard syndrome
65. Brown–Vialetto–Van Laere syndrome
66. Bruck syndrome
67. Brugada syndrome
68. Brunner syndrome
69. Budd–Chiari syndrome
70. Burning feet syndrome
71. Burning mouth syndrome
72. Burnside–Butler syndrome
73. Buschke–Ollendorff syndrome
74. Bálint's syndrome
75. Börjeson-Forssman-Lehmann syndrome

1. CADASIL
2. Camera-Marugo-Cohen syndrome
3. CAMFAK syndrome
4. Camptodactyly-arthropathy-coxa vara-pericarditis syndrome
5. Cancer syndrome
6. Cancer-related fatigue
7. CANDLE syndrome
8. Canine epileptoid cramping syndrome
9. Cannabinoid hyperemesis syndrome (CHS)
10. Cantú syndrome
11. Capgras delusion
12. Capgras syndrome
13. Capillary leak syndrome
14. Caplan's syndrome
15. Carcinoid syndrome
16. Cardiac syndrome X
17. Cardiofaciocutaneous syndrome
18. Cardiorenal syndrome
19. Cardiovascular syndrome
20. Carney complex
21. Caroli disease
22. Carpal tunnel syndrome
23. Carpenter syndrome
24. Cat eye syndrome
25. Cataract-microcornea syndrome
26. Catastrophic antiphospholipid syndrome
27. Catel–Manzke syndrome
28. Cauda equina syndrome
29. Caudal regression syndrome
30. CDK13-related disorder
31. Celebrity worship syndrome
32. Central centrifugal cicatricial alopecia
33. Central cord syndrome
34. Central nervous system syndrome
35. Central pain syndrome
36. Centurion syndrome
37. Cerebellar cognitive affective syndrome
38. Cerebellar stroke syndrome
39. Cerebellopontine angle syndrome
40. Cerebral salt-wasting syndrome
41. Cervicocranial syndrome
42. Charcot–Marie–Tooth disease
43. CHARGE syndrome
44. Charles Bonnet syndrome
45. Chiari–Frommel syndrome
46. Chiasmal syndrome
47. Chilaiditi syndrome
48. Child sexual abuse accommodation syndrome
49. CHILD syndrome
50. childhood myelodysplastic syndrome
51. Childhood tumor syndrome
52. Chinese Restaurant Syndrome
53. Chromosomal deletion syndrome
54. Chromosome 5q deletion syndrome
55. Chronic fatigue syndrome
56. Chronic functional abdominal pain
57. Chronic infantile neurologic cutaneous and articular syndrome
58. Chronic Lyme disease
59. Chronic prostatitis/chronic pelvic pain syndrome
60. Churg–Strauss syndrome
61. Chédiak–Higashi syndrome
62. Claude's syndrome
63. Clinically isolated syndrome
64. CLOVES syndrome
65. COACH syndrome
66. Cobb syndrome
67. Cockayne syndrome
68. Coffin–Lowry syndrome
69. Coffin–Siris syndrome
70. Cogan syndrome
71. Cohen syndrome
72. Compartment syndrome
73. Complement deficiency
74. Complete androgen insensitivity syndrome
75. Complex regional pain syndrome
76. Computer vision syndrome
77. Conductive deafness-ptosis-skeletal anomalies syndrome
78. Congenital bilateral perisylvian syndrome
79. Congenital contractural arachnodactyly
80. Congenital generalized lipodystrophy
81. Congenital insensitivity to pain
82. Congenital myasthenic syndrome
83. Congenital nephrotic syndrome
84. Congenital rubella syndrome
85. Conn's syndrome
86. Conorenal syndrome
87. Conradi–Hünermann syndrome
88. Constriction ring syndrome
89. Contiguous gene syndrome
90. Conus medullaris syndrome
91. Cooks syndrome
92. Cord colitis syndrome
93. Corneal-cerebellar syndrome
94. Corneal dystrophy-perceptive deafness syndrome
95. Cornelia de Lange Syndrome
96. Corneodermatoosseous syndrome
97. Coronary steal
98. Costeff syndrome
99. Costello syndrome
100. Cotard delusion
101. Cotard's Syndrome
102. Cotton fever
103. Cowden syndrome
104. Cracked tooth syndrome
105. Cramp fasciculation syndrome
106. Crandall syndrome
107. Craniosynostosis–anal anomalies–porokeratosis syndrome
108. Cranio-lenticulo-sutural dysplasia
109. CREST syndrome
110. Cri du chat
111. Crigler–Najjar syndrome
112. Crome syndrome
113. Cronkhite–Canada syndrome
114. Cross syndrome
115. Crouzon syndrome
116. Crouzonodermoskeletal syndrome
117. Crush syndrome
118. Cruveilhier-Baumgarten syndrome
119. Cryopyrin-associated periodic syndrome
120. Cryptorchidism-arachnodactyly-intellectual disability syndrome
121. Cuboid syndrome
122. Currarino syndrome
123. Cushing's syndrome
124. Cyclic vomiting syndrome
125. Cytokine release syndrome

1. Da Costa's syndrome
2. Daentl Townsend Siegel syndrome
3. Dahlberg Borer Newcomer syndrome
4. Dandy–Walker syndrome
5. De Barsy syndrome
6. de Clérambault's syndrome
7. De Quervain syndrome
8. De Winter syndrome
9. Dead arm syndrome
10. Deficiency of the interleukin-1–receptor antagonist
11. Degenerative disc disease
12. Dejerine–Roussy syndrome
13. Delayed sleep phase disorder
14. Delusional misidentification syndrome
15. Delusional parasitosis
16. Dennie–Marfan syndrome
17. Dentomandibular sensorimotor dysfunction
18. Denys–Drash syndrome
19. DeSanctis–Cacchione syndrome
20. Descending perineum syndrome
21. Diabetic stiff hand syndrome
22. Dialysis disequilibrium syndrome
23. Diencephalic syndrome
24. Diffuse infiltrative lymphocytosis syndrome
25. DiGeorge syndrome
26. Diogenes syndrome
27. Diploid-triploid mosaicism
28. Disconnection syndrome
29. Distal 18q-
30. Distal intestinal obstruction syndrome
31. Distal trisomy 10q
32. Doege–Potter syndrome
33. Donnai–Barrow syndrome
34. Donohue syndrome
35. DOOR syndrome
36. Dopamine dysregulation syndrome
37. Down syndrome
38. Dravet syndrome
39. Dressler syndrome
40. Drug reaction with eosinophilia and systemic symptoms
41. Dry eye syndrome
42. Duane syndrome
43. Duane-radial ray syndrome
44. Dubin–Johnson syndrome
45. Dubowitz syndrome
46. Dumping syndrome
47. Dysexecutive syndrome
48. Dyskeratosis congenita
49. Dysplastic nevus syndrome

1. Eagle syndrome
2. Ectrodactyly–ectodermal dysplasia–cleft syndrome
3. Edwards syndrome
4. EEM syndrome
5. Egg drop syndrome
6. Ehlers–Danlos syndrome
7. Eiken syndrome
8. Einstein syndrome
9. Eisenmenger's syndrome
10. Eldomery-Sutton syndrome
11. Elejalde syndrome
12. Ellis–van Creveld syndrome
13. Emanuel syndrome
14. Empty nest syndrome
15. Empty nose syndrome
16. Empty sella syndrome
17. Enlarged vestibular aqueduct syndrome
18. Environmental dependency syndrome
19. Eosinophilia–myalgia syndrome
20. Eosinophilic cellulitis
21. Epidermal nevus syndrome
22. Epilepsy syndromes
23. Episodic dyscontrol syndrome
24. Epizootic ulcerative syndrome
25. Erdheim–Chester disease
26. Erondu–Cymet syndrome
27. Estrogen insensitivity syndrome
28. Euthyroid sick syndrome
29. Evans syndrome
30. Excess ovarian androgen release syndrome
31. Exploding head syndrome
32. Extrapyramidal symptoms

1. FACES syndrome
2. Facet syndrome
3. Facial Onset Sensory Motor Neuropathy syndrome
4. Fahr's syndrome
5. Failed back syndrome
6. Familial cold autoinflammatory syndrome
7. Familial Mediterranean fever
8. Familial partial lipodystrophy
9. Familial Adenomatous Polyposis
10. Fanconi syndrome
11. Favre–Racouchot syndrome
12. Febrile infection-related epilepsy syndrome
13. Febrile neutrophilic dermatosis
14. Fechtner syndrome
15. Feingold syndrome
16. Feline hyperesthesia syndrome
17. Felty's syndrome
18. Femur fibula ulna syndrome
19. Fetal alcohol syndrome
20. Fetal hydantoin syndrome
21. Fetal trimethadione syndrome
22. Fetal valproate syndrome
23. Fetal warfarin syndrome
24. FG syndrome
25. Fibrinolysis syndrome
26. Fibromyalgia syndrome
27. Fibromyalgia
28. First arch syndrome
29. Fish acute toxicity syndrome
30. Fitz-Hugh–Curtis syndrome
31. Fitzsimmons–Guilbert syndrome
32. Flammer syndrome
33. Fleischer's syndrome
34. Floating–Harbor syndrome
35. Floppy eyelid syndrome
36. Floppy trunk syndrome
37. Florid cutaneous papillomatosis
38. Flynn–Aird syndrome
39. Foal immunodeficiency syndrome
40. Foerster's syndrome
41. Foix–Alajouanine syndrome
42. Foix–Chavany–Marie syndrome
43. Folie à deux
44. Follicle-stimulating hormone insensitivity
45. Forbes-Albright syndrome
46. Foreign accent syndrome
47. Foster–Kennedy syndrome
48. Fountain syndrome
49. Foville's syndrome
50. Fragile X syndrome
51. Fragile X-associated tremor/ataxia syndrome
52. Franceschetti–Klein syndrome
53. Frank–ter Haar syndrome
54. Fraser syndrome
55. Frasier syndrome
56. Freeman–Sheldon syndrome
57. Frey's syndrome
58. Froin's syndrome
59. Fryns syndrome
60. Functional somatic syndrome

1. Gaisböck syndrome
2. Galloway Mowat syndrome
3. GAPO syndrome
4. Gardner's syndrome
5. Gastric outlet obstruction
6. Gastrocutaneous syndrome
7. Gastrointestinal syndrome
8. Genitopatellar syndrome
9. Gerstmann syndrome
10. Gerstmann–Sträussler–Scheinker syndrome
11. Geschwind syndrome
12. Gianotti–Crosti syndrome
13. Giant platelet disorder
14. Guillain–Barré syndrome
15. Gillespie syndrome
16. Gitelman syndrome
17. Gleich's syndrome
18. GMS syndrome
19. Goldberg–Shprintzen syndrome
20. Goldenhar syndrome
21. Gomez and López-Hernández syndrome
22. Gonadotropin insensitivity
23. Gonadotropin-releasing hormone insensitivity
24. Goodpasture syndrome
25. Gordon syndrome
26. Gougerot–Blum syndrome
27. Gourmand syndrome
28. Gouverneur's syndrome
29. GRACILE syndrome
30. Graham-Little syndrome
31. Gray baby syndrome
32. Gray platelet syndrome
33. Greater trochanteric pain syndrome
34. Green nail syndrome
35. Greig cephalopolysyndactyly syndrome
36. Grinspan's syndrome
37. Griscelli syndrome type 2
38. Griscelli syndrome type 3
39. Griscelli syndrome
40. Grisel's syndrome
41. Growing teratoma syndrome
42. Gilbert's syndrome
43. Gulf War syndrome

1. Haber syndrome
2. Hagemoser–Weinstein–Bresnick syndrome
3. Haglund's syndrome
4. Haim–Munk syndrome
5. Hajdu–Cheney syndrome
6. Halal syndrome
7. Hallermann–Streiff syndrome
8. Hamman's syndrome
9. Hamman-Rich syndrome
10. Hand-foot-genital syndrome
11. Handigodu syndrome
12. Hanhart syndrome
13. Hantavirus pulmonary syndrome
14. Hapnes Boman Skeie syndrome
15. Harlequin syndrome
16. Harris platelet syndrome
17. Harrison syndrome
18. Havana syndrome
19. Hay–Wells syndrome
20. Hearing loss with craniofacial syndromes
21. HEC syndrome
22. Heel pad syndrome
23. Heel spur syndrome
24. Heerfordt syndrome
25. HELLP syndrome
26. Hemihyperplasia–multiple lipomatosis syndrome
27. Hemimegalencephaly
28. Hemispatial neglect
29. Hemoglobin Lepore syndrome
30. Hemolytic-uremic syndrome
31. Hennekam syndrome
32. Hepatopulmonary syndrome
33. Hepatorenal syndrome
34. Hereditary breast–ovarian cancer syndrome
35. Hereditary hyperbilirubinemia
36. Hereditary leiomyomatosis and renal cell cancer syndrome
37. Hereditary neuralgic amyotrophy
38. Hereditary nonpolyposis colorectal cancer
39. Hermansky–Pudlak syndrome
40. Hero syndrome
41. Heyde's syndrome
42. High-rise syndrome
43. HIV/AIDS
44. Holiday heart syndrome
45. Holt–Oram syndrome
46. Horn-Kolb syndrome
47. Horner's syndrome
48. Howel–Evans syndrome
49. Hoyeraal-Hreidarsson syndrome
50. Ho–Kaufman–Mcalister syndrome
51. Hughes–Stovin syndrome
52. Hunan hand syndrome
53. Hunter syndrome
54. Huntington's disease-like syndrome
55. HUPRA syndrome
56. Hurler syndrome
57. Hurler–Scheie syndrome
58. Hutchinson–Gilford progeria syndrome
59. Hydrolethalus syndrome
60. Hyper IgM syndrome
61. Hyper-IgD syndrome
62. Hyper-IgM syndrome type 1
63. Hyper-IgM syndrome type 2
64. Hyper-IgM syndrome type 3
65. Hyper-IgM syndrome type 4
66. Hyper-IgM syndrome type 5
67. Hyperimmunoglobulin D syndrome
68. Hyperimmunoglobulin E syndrome
69. Hypermobility syndrome
70. Hyperosmolar syndrome
71. Hyperprolactinaemia
72. Hyperprolactinemic SAHA syndrome
73. Hypertension and brachydactyly syndrome
74. Hypertrichosis cubiti
75. Hyperventilation syndrome
76. Hyperviscosity syndrome
77. Hypohidrotic ectodermal dysplasia
78. Hypoplastic left heart syndrome
79. Hypoplastic right heart syndrome
80. Hypotonia
81. Hypotrichosis–acro-osteolysis–onychogryphosis–palmoplantar keratoderma–periodontitis syndrome
82. Hypotrichosis–lymphedema–telangiectasia syndrome
83. Hystrix-like ichthyosis–deafness syndrome

1. Ichthyosis follicularis with alopecia and photophobia syndrome
2. Ichthyosis prematurity syndrome
3. Idiopathic pneumonia syndrome
4. Idiopathic postprandial syndrome
5. Idiopathic pure sudomotor failure
6. Iliotibial band syndrome
7. Imerslund–Gräsbeck syndrome
8. Immersion foot syndromes
9. Immune reconstitution inflammatory syndrome
10. Immunodeficiency–centromeric instability–facial anomalies syndrome
11. Impingement syndrome
12. Imposter syndrome
13. Incontinentia pigmenti
14. Infant respiratory distress syndrome
15. Inferior vena cava syndrome
16. Infertility in polycystic ovary syndrome
17. Influenza-like illness
18. Institutional syndrome
19. Intersection syndrome
20. Interstitial cystitis
21. Intracranial hypertension syndrome
22. Intraoperative floppy iris syndrome
23. Intravenous marijuana syndrome
24. IPEX syndrome
25. Iridocorneal endothelial syndrome
26. Irlen syndrome
27. Irregular sleep–wake rhythm
28. irritable bladder syndrome
29. Irritable bowel syndrome
30. Irritable male syndrome
31. Irukandji syndrome
32. Irvine–Gass syndrome

1. Jackson–Weiss syndrome
2. Jacobsen syndrome
3. Jaffe–Campanacci syndrome
4. Jalili syndrome
5. Jansen's metaphyseal chondrodysplasia
6. Janz syndrome
7. Jeavons syndrome
8. Jervell and Lange-Nielsen syndrome
9. Johanson–Blizzard syndrome
10. Johnson–McMillin syndrome
11. Johnson–Munson syndrome
12. Joubert syndrome
13. Juberg-Hellman syndrome
14. Jugular foramen syndrome
15. Juvenile polyposis syndrome
16. Jerusalem syndrome

1. Kabuki syndrome
2. Kallmann syndrome
3. Kapur–Toriello syndrome
4. Karak syndrome
5. Karsch-Neugebauer syndrome
6. Kartagener's syndrome
7. Kasabach–Merritt syndrome
8. Katz syndrome
9. Kaufman oculocerebrofacial syndrome
10. Kearns–Sayre syndrome
11. Keppen–Lubinsky syndrome
12. Keratitis–ichthyosis–deafness syndrome
13. Keratosis linearis with ichthyosis congenita and sclerosing keratoderma syndrome
14. Keutel syndrome
15. Khyâl cap
16. Kimmelstiel-Wilson syndrome
17. Kindler syndrome
18. King–Kopetzky syndrome
19. Kleine–Levin syndrome
20. Klinefelter syndrome
21. Klippel–Feil syndrome
22. Klippel–Trénaunay syndrome
23. Klüver–Bucy syndrome
24. Knobloch syndrome
25. Kocher–Debre–Semelaigne syndrome
26. Kohlschütter-Tönz syndrome
27. Korsakoff's syndrome
28. Kostmann syndrome
29. Kounis syndrome
30. Kowarski syndrome
31. Kufor–Rakeb syndrome
32. König's syndrome

1. Lachiewicz–Sibley syndrome
2. Lacunar Stroke Syndrome
3. Lambert–Eaton myasthenic syndrome
4. Landau–Kleffner syndrome
5. Langer–Giedion syndrome
6. Laron syndrome
7. Larsen syndrome
8. Laryngoonychocutaneous syndrome
9. Lateral medullary syndrome
10. Lateral meningocele syndrome
11. Lateral pontine syndrome
12. Laugier–Hunziker syndrome
13. Laurence–Moon syndrome
14. Lavender foal syndrome
15. Lawrence–Seip syndrome
16. Lazarus syndrome
17. Leaky gut syndrome
18. Legg–Calvé–Perthes disease
19. Legius syndrome
20. Leiner's disease
21. Lelis syndrome
22. Lemierre's syndrome
23. Lennox–Gastaut syndrome
24. Lenz microphthalmia syndrome
25. Lenz–Majewski syndrome
26. Leriche's syndrome
27. Leschke syndrome
28. Lesch–Nyhan syndrome
29. Lethal congenital contracture syndrome
30. Lethal white syndrome
31. Leukotriene receptor antagonist-associated Churg–Strauss syndrome
32. Levator ani syndrome
33. Leydig cell hypoplasia
34. Liddle's syndrome
35. Liebenberg syndrome
36. LIG4 syndrome
37. Lima syndrome
38. Limb girdle syndrome
39. Limber tail syndrome
40. Limb–mammary syndrome
41. Linburg–Comstock syndrome
42. Li–Fraumeni syndrome
43. Locked-in syndrome
44. Locomotive syndrome
45. Loeys–Dietz syndrome
46. Loin pain hematuria syndrome
47. Long COVID
48. Long face syndrome
49. Long QT syndrome
50. Loose anagen syndrome
51. Lown–Ganong–Levine syndrome
52. Lowry–MacLean syndrome
53. Lucey–Driscoll syndrome
54. Lujan–Fryns syndrome
55. Lutembacher's syndrome
56. Lymphangitis carcinomatosa
57. Lymphedema–distichiasis syndrome
58. Lynch syndrome
59. Lyngstadaas syndrome
60. Löffler's syndrome
61. Löfgren syndrome

1. M74 syndrome
2. Macrocephaly-capillary malformation
3. Macrophage activation syndrome
4. Maffucci syndrome
5. Majeed syndrome
6. Majewski's polydactyly syndrome
7. Mal de debarquement
8. Malformative syndrome
9. Mallory–Weiss syndrome
10. Malnutrition–inflammation complex
11. Malouf syndrome
12. Malpuech facial clefting syndrome
13. Management of chronic headaches
14. Manning criteria
15. Marchiafava–Bignami disease
16. Marden–Walker syndrome
17. Mare reproductive loss syndrome
18. Marfan syndrome
19. Marfanoid–progeroid–lipodystrophy syndrome
20. Marie Antoinette syndrome
21. Marinesco–Sjögren syndrome
22. Maroteaux–Lamy syndrome
23. Marshall syndrome
24. Marshall–Smith syndrome
25. Marshall–White syndrome
26. MASA syndrome
27. Mast cell activation syndrome
28. Mauriac syndrome
29. Mayer–Rokitansky–Küster–Hauser syndrome
30. May–Thurner syndrome
31. May–White syndrome
32. McArdle syndrome
33. McCune–Albright syndrome
34. McCusick syndrome
35. McGillivray syndrome
36. McKittrick–Wheelock syndrome
37. McKusick–Kaufman syndrome
38. McLeod syndrome
39. MDP syndrome
40. Mean world syndrome
41. Meckel syndrome
42. Meconium aspiration syndrome
43. Medial medullary syndrome
44. Medial pontine syndrome
45. Median arcuate ligament syndrome
46. Medical students' disease
47. MEDNIK syndrome
48. Megavitamin-B₆ syndrome
49. Meige's syndrome
50. Meigs' syndrome
51. MELAS syndrome
52. Melkersson–Rosenthal syndrome
53. Melnick–Needles syndrome
54. Memory distrust syndrome
55. Mendelson's syndrome
56. Ménière's disease
57. Menkes disease
58. MERRF syndrome
59. Metabolic syndrome
60. Michelin tire baby syndrome
61. Michels Caskey syndrome
62. Michels syndrome
63. Mickleson syndrome
64. Micro syndrome
65. Microdeletion syndrome
66. Microphthalmia–dermal aplasia–sclerocornea syndrome
67. Middle cerebral artery syndrome
68. Middle child syndrome
69. Middle East respiratory syndrome
70. Mikulicz syndrome
71. Mild androgen insensitivity syndrome
72. Milk-alkali syndrome
73. Millard–Gubler syndrome
74. Miller Fisher syndrome
75. Miller syndrome
76. Miller–Dieker syndrome
77. Milroy's disease
78. Milwaukee shoulder syndrome
79. Mirhosseini–Holmes–Walton syndrome
80. Mirizzi's syndrome
81. Mirror syndrome
82. Mismatch repair cancer syndrome
83. Mitochondrial DNA depletion syndrome
84. Mitochondrial neurogastrointestinal encephalopathy syndrome
85. Mitral valve prolapse
86. Mittelschmerz
87. Mohr–Tranebjærg syndrome
88. MOMO syndrome
89. Monofixation syndrome
90. MonoMAC
91. Morgagni Stewart Morel syndrome
92. MORM syndrome
93. Morquio syndrome
94. Morvan's syndrome
95. Mouth and genital ulcers with inflamed cartilage syndrome
96. Mowat–Wilson syndrome
97. Moyamoya disease
98. Moynahan syndrome
99. Muckle–Wells syndrome
100. Muenke syndrome
101. Muir–Torre syndrome
102. Mukamel syndrome
103. Multiple endocrine neoplasia type 1
104. Multiple endocrine neoplasia type 2
105. Multiple evanescent white dot syndrome
106. Multiple hamartoma syndrome
107. Multiple organ dysfunction syndrome
108. Multiple pterygium syndrome
109. Munchausen syndrome
110. Mungan syndrome
111. Musical ear syndrome
112. Mycosis fungoides
113. Myelodysplastic syndrome
114. Myoclonic astatic epilepsy
115. Myofascial pain syndrome
116. Myomatous erythrocytosis syndrome
117. Möbius syndrome
118. Müllerian agenesis

1. Nablus mask-like facial syndrome
2. Naegeli–Franceschetti–Jadassohn syndrome
3. Nager acrofacial dysostosis
4. Nail–patella syndrome
5. Nakajo syndrome
6. Nance–Horan syndrome
7. Napoleonist Syndrome
8. Nasodigitoacoustic syndrome
9. Naxos syndrome
10. Nelson's syndrome
11. NEMO deficiency syndrome
12. Neonatal ichthyosis–sclerosing cholangitis syndrome
13. Nephritic syndrome
14. Nephrotic syndrome
15. Nerve compression syndrome
16. Netherton syndrome
17. Neu–Laxova syndrome
18. Neuro-cardio-facial-cutaneous syndromes
19. Neurofibromatosis type I
20. Neuroleptic malignant syndrome
21. Neuroleptic-Induced Deficit Syndrome
22. Neutrophil immunodeficiency syndrome
23. Nevo syndrome
24. Nevoid basal-cell carcinoma syndrome
25. Nezelof syndrome
26. Nicolaides–Baraitser syndrome
27. Nicolau–Balus syndrome
28. Night eating syndrome
29. Nijmegen breakage syndrome
30. Njølstad syndrome
31. Nodding disease
32. Non-24-hour sleep–wake disorder
33. Noonan syndrome with multiple lentigines
34. Noonan syndrome
35. Norman–Roberts syndrome
36. Northern epilepsy syndrome
37. Nutcracker syndrome

1. Occipital horn syndrome
2. Ocular ischemic syndrome
3. Oculo-respiratory syndrome
4. Oculoauricular syndrome
5. Oculocerebrocutaneous syndrome
6. Oculocerebrorenal syndrome
7. Oculofaciocardiodental syndrome
8. Oculomucocutaneous syndrome
9. Odontoma dysphagia syndrome
10. Odonto–tricho–ungual–digital–palmar syndrome
11. Ogden Syndrome
12. Ogilvie syndrome
13. Ohtahara syndrome
14. Olfactory reference syndrome
15. Oliver–McFarlane syndrome
16. Omenn syndrome
17. One and a half syndrome
18. Oneiroid syndrome
19. Opitz G/BBB Syndrome
20. Opsoclonus myoclonus syndrome
21. Oral allergy syndrome
22. Oral mite anaphylaxis
23. Oral-facial-digital syndrome
24. Orbital apex syndrome
25. Organic brain syndrome
26. Organic dust toxic syndrome
27. Orofaciodigital syndrome 1
28. Ortner's syndrome
29. OSLAM syndrome
30. Osler–Weber–Rendu disease
31. Otodental syndrome
32. Otofacial syndrome
33. Ovarian hyperstimulation syndrome
34. Ovarian vein syndrome
35. Overgrowth syndrome
36. Overlap syndrome

1. Pacak–Zhuang syndrome
2. Pacemaker syndrome
3. Painful bruising syndrome
4. Pallister–Hall syndrome
5. Pallister–Killian syndrome
6. Panayiotopoulos syndrome
7. Pancoast tumor
8. Pantothenate kinase-associated neurodegeneration
9. PAPA syndrome
10. Papillon–Lefèvre syndrome
11. Papillorenal syndrome
12. Papular purpuric gloves and socks syndrome
13. Paraneoplastic acrokeratosis
14. Paraneoplastic cerebellar degeneration
15. Paraneoplastic syndrome
16. Parental alienation syndrome
17. Parinaud's oculoglandular syndrome
18. Parinaud's syndrome
19. Paris-Trousseau syndrome
20. Parkes Weber syndrome
21. Parkinson plus syndrome
22. Paroxysmal hand hematoma
23. Paroxysmal tachycardia
24. Parry–Romberg syndrome
25. Parsonage–Turner syndrome
26. Partial androgen insensitivity syndrome
27. Pashayan syndrome
28. Patau syndrome
29. Patellar subluxation syndrome
30. Patellofemoral pain syndrome
31. Patterson syndrome
32. Pearson syndrome
33. PANDAS
34. Peeling skin syndrome
35. PEHO syndrome
36. Pellegrini–Stieda syndrome
37. Pelvic congestion syndrome
38. Pelvic pain
39. Pemphigus erythematosus
40. Pendred syndrome
41. Penile Artery Shunt Syndrome
42. Pentalogy of Cantrell
43. Periodic fever syndrome
44. Periodic fever, aphthous stomatitis, pharyngitis and adenitis
45. Perisylvian syndrome
46. Perlman syndrome
47. Persistent adrenarche syndrome
48. Persistent genital arousal disorder
49. Persistent Müllerian duct syndrome
50. Pervasive refusal syndrome
51. Peters-plus syndrome
52. Peutz–Jeghers syndrome
53. Pfeiffer syndrome
54. Phantom eye syndrome
55. Phantom limb
56. Phantom vibration syndrome
57. Phelan-McDermid Syndrome
58. Pickwickian syndrome
59. Pigment dispersion syndrome
60. Pigmented hairy epidermal nevus syndrome
61. Pilotto syndrome
62. Piriformis syndrome
63. Pitt–Hopkins syndrome
64. Plica syndrome
65. Plummer–Vinson syndrome
66. POEMS syndrome
67. Poland syndrome
68. Polar T3 syndrome
69. Polio-like syndrome
70. Polycystic ovary syndrome
71. Popliteal artery entrapment syndrome
72. Popliteal pterygium syndrome
73. Porcine stress syndrome
74. Pork–cat syndrome
75. Post-micturition convulsion syndrome
76. Post-nasal drip syndrome
77. Post-traumatic stress syndrome
78. Post-acute-withdrawal syndrome
79. Post-concussion syndrome
80. Post-Ebola virus syndrome
81. Post-intensive care syndrome
82. Post-maturity syndrome
83. Post-polio syndrome
84. Post-thrombotic syndrome
85. Post-vasectomy pain syndrome
86. Postcardiotomy syndrome
87. Postcholecystectomy syndrome
88. Posterior cerebral artery syndrome
89. Posterior cord syndrome
90. Posterior rami syndrome
91. Posterior reversible encephalopathy syndrome
92. Postgastrectomy syndromes
93. Postorgasmic illness syndrome
94. Postperfusion syndrome
95. Postpericardiotomy syndrome
96. Postural orthostatic tachycardia syndrome
97. Potocki–Lupski syndrome
98. Potocki–Shaffer syndrome
99. Potter sequence
100. Prader–Willi syndrome
101. Pre-excitation syndrome
102. Precordial catch syndrome
103. Premenstrual syndrome
104. Presumed ocular histoplasmosis syndrome
105. Pretzel syndrome
106. Primary pigmented nodular adrenocortical disease
107. Primrose syndrome
108. Progeroid syndromes
109. Progressive supranuclear palsy
110. Prolonged grief disorder
111. Pronator teres syndrome
112. Propofol infusion syndrome
113. Proteus syndrome
114. Proteus-like syndrome
115. Prune belly syndrome
116. Pseudo-Cushing's syndrome
117. Pseudodementia
118. Pseudoexfoliation syndrome
119. Psychoorganic syndrome
120. Puer aeternus
121. Pulmonary-renal syndrome
122. Purple glove syndrome
123. Purple urine bag syndrome

1. Qazi–Markouizos syndrome
2. Quadrilateral space syndrome
3. Queen bee syndrome

1. Rabbit syndrome
2. Rabson–Mendenhall syndrome
3. Radial tunnel syndrome
4. Rage syndrome
5. Raghib syndrome
6. Raine syndrome
7. Ramos-Arroyo syndrome
8. Ramsay Hunt syndrome type 1
9. Ramsay Hunt syndrome type 2
10. Ramsay Hunt syndrome
11. RAPADILINO syndrome
12. Rape trauma syndrome
13. Rapp–Hodgkin syndrome
14. Rapunzel syndrome
15. Rasmussen syndrome
16. RASopathy
17. Raymond Céstan syndrome
18. Raynaud syndrome
19. Red ear syndrome
20. Red man syndrome (Drug eruption)
21. Refeeding syndrome
22. Reactive arthritis
23. Renal dysplasia-limb defects syndrome
24. Renfield syndrome
25. Renpenning's syndrome
26. Restless legs syndrome
27. Restrictive dermopathy
28. Retinoic acid syndrome
29. Retirement syndrome
30. Rett syndrome
31. Reversible cerebral vasoconstriction syndrome
32. Revesz syndrome
33. Reye syndrome
34. Reynolds syndrome
35. Reynolds' pentad
36. Rh deficiency syndrome
37. Riddoch syndrome
38. Right middle lobe syndrome
39. Riley-Day Syndrome
40. Riley–Day syndrome
41. Ring chromosome 14 syndrome
42. Ring chromosome 20 syndrome
43. Roberts syndrome
44. Robinow syndrome
45. Rochon-Duvigneaud's syndrome
46. Roemheld syndrome
47. ROHHAD
48. Romano–Ward syndrome
49. Rombo syndrome
50. Rosenthal syndrome
51. Rosenthal–Kloepfer syndrome
52. Ross' syndrome
53. Rosselli–Gulienetti syndrome
54. Rothmund–Thomson syndrome
55. Rotor syndrome
56. Roussy–Lévy syndrome
57. Rubinstein–Taybi syndrome
58. Rud syndrome
59. Rudiger syndrome
60. Rumination syndrome
61. Runting-stunting syndrome in broilers
62. Ruzicka Goerz Anton syndrome

1. Saal Bulas syndrome
2. Saal Greenstein syndrome
3. Sabinas brittle hair syndrome
4. Sack–Barabas syndrome
5. SACRAL syndrome
6. Saethre–Chotzen syndrome
7. SAHA syndrome
8. Sakati–Nyhan–Tisdale syndrome
9. Salt water aspiration syndrome
10. Sandifer syndrome
11. Sanfilippo syndrome
12. Sanjad-Sakati syndrome
13. SAPHO syndrome
14. Satoyoshi syndrome
15. Savant syndrome
16. Say syndrome
17. Say–Meyer syndrome
18. Scalp–ear–nipple syndrome
19. SCARF syndrome
20. Scheie syndrome
21. Schimmelpenning syndrome
22. Schinzel–Giedion syndrome
23. Schmitt Gillenwater Kelly syndrome
24. Schnitzler syndrome
25. Schwartz–Jampel syndrome
26. Schöpf–Schulz–Passarge syndrome
27. Scimitar syndrome
28. Scott syndrome
29. Seaver Cassidy syndrome
30. Seckel syndrome
31. Second-impact syndrome
32. Secretan's syndrome
33. Seed dispersal syndrome
34. Senior–Løken syndrome
35. Sensenbrenner syndrome
36. Septo-optic dysplasia
37. Serkal syndrome
38. Serotonin syndrome
39. Serpentine fibula-polycystic kidney syndrome
40. Sertoli cell-only syndrome
41. Serum sickness–like reaction
42. Setleis syndrome
43. Severe acute respiratory syndrome
44. Shaken baby syndrome
45. Shapiro syndrome
46. Sheehan's syndrome
47. Shell nail syndrome
48. Shone's syndrome
49. Short anagen syndrome
50. Short bowel syndrome
51. Short man syndrome
52. Short QT syndrome
53. Short rib – polydactyly syndrome
54. SHORT syndrome
55. Shwachman–Diamond syndrome
56. Shy-Drager syndrome
57. Sick building syndrome
58. Sick sinus syndrome
59. Silver–Russell syndrome
60. Simpson–Golabi–Behmel syndrome
61. Singleton Merten syndrome
62. Situs ambiguus
63. Sjögren's syndrome
64. Sjögren–Larsson syndrome
65. Skeeter syndrome
66. Skin fragility syndrome
67. Sliding uncus syndrome
68. Sly syndrome
69. Small intestinal bacterial overgrowth
70. Small Penis Syndrome
71. Smith Martin Dodd syndrome
72. Smith–Fineman–Myers syndrome
73. Smith–Lemli–Opitz syndrome
74. Smith–Magenis syndrome
75. Snapping hip syndrome
76. Snapping scapula syndrome
77. Sneddon's syndrome
78. Solipsism syndrome
79. somatostatinoma syndrome
80. Sopite syndrome
81. Sotos syndrome
82. Space adaptation syndrome
83. Spastic ataxia-corneal dystrophy syndrome
84. Spider lamb syndrome
85. Splenic flexure syndrome
86. Split hand syndrome
87. Spondylo-ocular syndrome
88. SPRED1
89. Staphylococcal scalded skin syndrome
90. STAR syndrome
91. Stauffer syndrome
92. Stendhal syndrome
93. Steroid dementia syndrome
94. Stevens–Johnson syndrome
95. Stewart–Treves syndrome
96. Stickler syndrome
97. Sticky platelet syndrome
98. Sticky skin syndrome
99. Stiff person syndrome
100. Stiff skin syndrome
101. Stimmler syndrome
102. Stockholm syndrome
103. Straight back syndrome
104. Stratton Parker syndrome
105. Streff syndrome
106. Strømme syndrome
107. Stuck song syndrome
108. Student syndrome
109. Sturge–Weber syndrome
110. Subclavian steal syndrome
111. Sudden death syndrome
112. Sudden infant death syndrome
113. Sudden wealth syndrome
114. Sugarman syndrome
115. Sulfonamide hypersensitivity syndrome
116. Summer penile syndrome
117. Sundowning
118. Superior mesenteric artery syndrome
119. Superior orbital fissure syndrome
120. Superior vena cava syndrome
121. Supernumerary nipples–uropathies–Becker's nevus syndrome
122. Supernumerary phantom limb
123. Survivor syndrome
124. Susac's syndrome
125. Sweet's syndrome
126. Swyer–James syndrome
127. Syndrome of inappropriate antidiuretic hormone secretion
128. Syndrome of subjective doubles
129. Syndrome Without A Name
130. HHH syndrome
131. Systemic inflammatory response syndrome
132. Sézary disease

1. TAFRO syndrome
2. Talk and die syndrome
3. TAN syndrome
4. TAR syndrome
5. Tardive dyskinesia
6. Tardive psychosis
7. Tarsal tunnel syndrome
8. Taura syndrome
9. Taussig–Bing syndrome
10. Tea and toast syndrome
11. TEMPI syndrome
12. Temple–Baraitser syndrome
13. Tension myositis syndrome
14. Terson syndrome
15. Testicular dysgenesis syndrome
16. Tetra-amelia syndrome
17. Tetralogy of Fallot
18. Teunissen–Cremers syndrome
19. Thevenard syndrome
20. Thoracic insufficiency syndrome
21. Thoracic outlet syndrome
22. Thrombotic thrombocytopenic purpura
23. Thymoma with immunodeficiency
24. Tietz syndrome
25. Tietze syndrome
26. Timothy syndrome
27. TNF receptor associated periodic syndrome
28. Tolosa–Hunt syndrome
29. Tonic tensor tympani syndrome
30. Tooth and nail syndrome
31. TORCH syndrome
32. Tourette syndrome
33. Townes–Brocks syndrome
34. Toxic anterior segment syndrome
35. Toxic oil syndrome
36. Toxic shock syndrome
37. Tracheobronchomegaly
38. Transurethral resection of the prostate syndrome
39. Transverse myelitis
40. Treacher Collins syndrome
41. Trench foot
42. Tricho-hepato-enteric syndrome
43. Trichothiodystrophy
44. Tricho–dento–osseous syndrome
45. Tricho–rhino–phalangeal syndrome
46. Trigeminal trophic syndrome
47. Triple X syndrome
48. Triploid syndrome
49. Trisomy 8
50. Tropical splenomegaly syndrome
51. Trotter's syndrome
52. Truman Syndrome
53. Tsukuhara syndrome
54. Tumor lysis syndrome
55. Tumor necrosis factor receptor associated periodic syndrome
56. Turner syndrome
57. Twiddler's syndrome
58. Twin Anemia-Polycythemia Sequence
59. Twin-to-twin transfusion syndrome

1. Ulysses syndrome
2. Uncombable hair syndrome
3. Uner Tan syndrome
4. Upper airway resistance syndrome
5. Upper motor neuron syndrome
6. Upshaw–Schulman syndrome
7. Urban survival syndrome
8. Urban–Rogers–Meyer syndrome
9. Urethral syndrome
10. Urofacial syndrome
11. Urticarial vasculitis
12. Usher syndrome
13. UV-sensitive syndrome

1. VACTERL association
2. Valentino's syndrome
3. Van der Woude syndrome
4. van Gogh syndrome
5. Van Wyk and Grumbach syndrome
6. Vanishing bile duct syndrome
7. Vascular access steal syndrome
8. Vasoplegic syndrome
9. Vestibulocerebellar syndrome
10. Vici syndrome
11. Villaret’s syndrome
12. VIP syndrome
13. VIPoma
14. Visual looming syndrome
15. Vitreous touch syndrome
16. Vogt–Koyanagi–Harada disease
17. Von Hippel–Lindau disease
18. Vulvodynia

1. Waardenburg syndrome
2. WAGR syndrome
3. Walker–Warburg syndrome
4. Wallis–Zieff–Goldblatt syndrome
5. Waltman Walter syndrome
6. Warkany syndrome 1
7. Warmblood Fragile Foal Syndrome
8. Wartenberg's Syndrome
9. Waterhouse–Friderichsen syndrome
10. Watson syndrome
11. Weaver syndrome
12. Weber's syndrome
13. Weill–Marchesani syndrome
14. Weismann-Netter–Stuhl syndrome
15. Weissenbacher–Zweymüller syndrome
16. Wellens' syndrome
17. Wende–Bauckus syndrome
18. Werner syndrome
19. Wernicke–Korsakoff syndrome
20. West syndrome
21. Westerhof syndrome
22. Wet lung syndrome in newborn
23. WHIM syndrome
24. White dog shaker syndrome
25. White dot syndromes
26. White spot syndrome
27. White-nose syndrome
28. Wiedemann-Steiner syndrome
29. Wiedemann–Rautenstrauch syndrome
30. Wildervanck syndrome
31. Williams syndrome
32. Williams–Campbell syndrome
33. Wilson's temperature syndrome
34. Wilson–Mikity syndrome
35. Wilson–Turner syndrome
36. Winchester syndrome
37. Winter-over syndrome
38. Wiskott–Aldrich syndrome
39. Wissler's syndrome
40. Withdrawal syndrome
41. Withering abalone syndrome
42. Wobbly hedgehog syndrome
43. Wolcott–Rallison syndrome
44. Wolff–Parkinson–White syndrome
45. Wolfram syndrome
46. Wolf–Hirschhorn syndrome
47. Woodhouse–Sakati syndrome
48. Work-related musculoskeletal disorders
49. Worster-Drought syndrome
50. Worth syndrome
51. Wrinkly skin syndrome

1. X-linked lymphoproliferative disease
2. Xeroderma pigmentosum
3. Xia-Gibbs Syndrome
4. XX male syndrome
5. XXXY syndrome
6. XXYY syndrome
7. XY gonadal dysgenesis
8. XYY syndrome

1. Yellow nail syndrome
2. Yemenite deaf-blind hypopigmentation syndrome
3. Yentl syndrome
4. Yim–Ebbin syndrome
5. Young's syndrome
6. Young–Madders syndrome
7. Young–Simpson syndrome
8. Yunis–Varon syndrome
9. Yunnan sudden death syndrome

1. Zadik–Barak–Levin syndrome
2. Zamzam–Sheriff–Phillips syndrome
3. Zechi-Ceide syndrome
4. Zellweger syndrome
5. Zieve's syndrome
6. Zimmermann–Laband syndrome
7. Zollinger–Ellison syndrome
8. Zori–Stalker–Williams syndrome