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Hirschsprung's disease |
Classification and external resources |
Histopathology of Hirschsprung disease. Enzyme histochemistry showing aberrant acetylcholine esterase (ACHE)-positive fibres (brown) in the lamina propria mucosae. |
ICD-10 |
Q43.1 |
ICD-9 |
751.3 |
OMIM |
142623 |
DiseasesDB |
5901 |
MedlinePlus |
001140 |
eMedicine |
med/1016 |
MeSH |
D006627 |
Hirschsprung disease (HD) is a disorder of the gut which is caused by the failure of the neural crest cells to migrate completely during fetal development of the intestine, eventually forming Auerbach's plexus. The affected segment of the colon fails to relax, causing an obstruction.[1] In the majority of affected people, the disorder affects the short segment of the distal colon. In rare cases the aganglionosis involves more of the colon. In 5 percent of cases the entire colon is affected. Hirschsprung is also sometimes called congenital aganglionic megacolon.
Hirschsprung disease occurs in approximately one in 5000 births in Japan.[2]
Contents
- 1 History and description
- 2 Etiology
- 3 Epidemiology
- 4 Genetic basis
- 5 Clinical features
- 6 Diagnosis
- 7 Treatment
- 7.1 Colostomy
- 7.2 Swenson, Soave, Duhamel, and Boley procedures
- 8 Associated syndromes
- 9 See also
- 10 References
- 11 External links
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History and description
The first report of Hirschsprung disease dates back to 1691,[3] however, the disease is named after Harald Hirschsprung, the Danish physician who first described two infants who died of this disorder in 1888.[4][5]
Hirschsprung’s disease is a congenital disorder of the colon in which certain nerve cells, known as ganglion cells, are absent, causing chronic constipation.[6] The lack of ganglion cells is in the myenteric plexus(Auerbach's Plexus), which is responsible for moving food in the intestine. A barium enema is the mainstay of diagnosis of Hirschsprung’s, though a rectal biopsy showing the lack of ganglion cells is the only certain method of diagnosis. The first publication on an important genetic discovery of the disease was from Martucciello Giuseppe et al. in 1992. The authors described a case of a patient with total colonic aganglionosis associated with a 46, XX, del 10 (q11.21 q21.2) karyotype.[7] The major gene of Hirschsprung disease was identified in this chromosomal 10 region, it was the RET proto-oncogene.[8]
The usual treatment is "pull-through" surgery where the portion of the colon that does have nerve cells is pulled through and sewn over the part that lacks nerve cells (National Digestive Diseases Information Clearinghouse). For a long time, Hirschsprung’s was considered a multi-factorial disorder, where a combination of nature and nurture were considered to be the cause. However, in August 1993, two articles by independent groups in Nature Genetics said that Hirschsprung’s disease could be mapped to a stretch of chromosome 10.[9][10]
This research also suggested that a single gene was responsible for the disorder. However, the researchers were unable to isolate it.
Etiology
The most accepted theory of the cause of Hirschsprung is that there is a defect in the craniocaudal migration of neuroblasts originating from the neural crest that occurs during the first 12 weeks of gestation. Defects in the differentiation of neuroblasts into ganglion cells and accelerated ganglion cell destruction within the intestine may also contribute to the disorder. [11]
Epidemiology
According to a 1984 study, Hirshsprung's disease appears on 18.6 per 100,000 live births. It is more common in male rather than female (4.32:1) and in white rather than non-white.[12] Nine percent of the Hirschsprung cases were also diagnosed as having Down's Syndrome.[13]
Genetic basis
Several genes and loci have been shown or suggested to be associated with Hirschsprung's disease:
Type |
OMIM |
Gene |
Locus |
HSCR1 |
142623 |
RET |
10q11.2 |
HSCR2 |
600155 |
EDNRB |
13q22 |
HSCR3 |
600837 |
GDNF |
5p13.1-p12 |
HSCR4 |
131242 |
EDN3 |
20q13.2-q13.3 |
HSCR5 |
600156 |
? |
21q22 |
HSCR6 |
606874 |
? |
3p21 |
HSCR7 |
606875 |
? |
19q12 |
HSCR8 |
608462 |
? |
16q23 |
HSCR9 |
611644 |
? |
4q31-32 |
– |
602229 |
SOX10 |
22q13 |
– |
600423 |
ECE1 |
1p36.1 |
– |
602018 |
NRTN |
19p13.3 |
– |
602595 |
SIP1 |
14q13-q21 |
Hirschsprung's disease can also present as part of a syndrome in Waardenburg-Shah syndrome, Mowat-Wilson syndrome, Goldberg-Shpritzen megacolon syndrome, and congenital central hypoventilation syndrome.[14]
The RET proto-oncogene accounts for the highest proportion of both familial and sporadic cases, with a wide range of mutations scattered along its entire coding region.[15]
In 2002, scientists thought they found the solution. The 2002 research suggests Hirschsprung's may be caused by the interaction between two proteins encoded by two variant genes. The RET proto-oncogene on chromosome 10 was identified as one of the genes involved. The protein with which RET has to interact in order for Hirschsprung’s disease to develop is termed EDNRB and is encoded by the gene EDNRB located on chromosome 13.
Hirschsprung's disease, hypoganglionosis, gut dysmotility, gut transit disorders and intussusception have been recorded with the dominantly inherited neurovisceral porphyrias (acute intermittent porphyria, hereditary coproporphyria, variegate porphyria). Children may require enzyme or DNA testing for these disorders as they may not produce or excrete porphyrins prepuberty.
RET proto-oncogene
RET codes for proteins that assist cells of the neural crest (which later become ganglion cells) in their movement through the digestive tract during the development of the embryo. EDNRB codes for proteins that connect these nerve cells to the digestive tract. This means that the absence of certain nerve fibers in the colon could be directly related to these two genes mutating so the wrong proteins are produced. Research published in June 2004 suggests that there are several genes associated with Hirschsprung’s disease.[16] Also, new research suggests that mutations in genomic sequences involved in regulating EDNRB have a bigger impact on Hirschsprung’s disease than previously thought.
RET can mutate in many ways and is associated with Down's syndrome. Since Down Syndrome is comorbid in two percent of Hirschsprung’s cases, there is a likelihood that RET is involved heavily in both Hirschprung's disease and Down Syndrome. RET is also associated with thyroid cancer and neuroblastoma. Both of these disorders have also been observed in Hirschsprung’s patients with greater frequency than in the general population. One function that RET controls is the travel of the neural crest cells through the intestines in the developing fetus. The earlier the mutation of RET occurs in Hirschsprung’s disease, the more severe the disorder becomes.
Clinical features
A: Plain abdominal radiograph showing a PARTZ at rectosigmoid, arrow. B: Plain abdominal radiograph showing a PARTZ at midsigmoid, arrow. C: Plain abdominal radiograph showing a PARTZ at descending colon, arrow. D: Contrast enema showing a CETZ at rectosigmoid, arrow. E: Contrast enema showing a CETZ at midsigmoid, arrow. F: Contrast enema showing a CETZ at descending colon, arrow.
With an incidence of 1/5000 births, the most cited feature is absence of ganglion cells: notably in males, 75% have none in the recto-sigmoid and 8% with none in the entire colon. The enlarged section of the bowel is found proximally, while the narrowed, aganglionic section is found distally. The absence of ganglion cells results in a persistent over-stimulation of nerves in the affected region, resulting in contraction.
- Delayed passage of meconium
- Abdominal distension
- Constipation
- Chronic Enterocolitis
Diagnosis
Hirschsprung's disease is suspected in a baby who has not passed meconium within 48 hours of delivery. Normally, 90% of babies pass their first meconium within 24 hours, and 99% within 48 hours. Other symptoms include, green or brown vomit, explosive stools after a doctor inserts a finger into the rectum, swelling of the abdomen, lots of gas and bloody diarrhea. Definitive diagnosis is made by suction biopsy of the distally narrowed segment.[17]
Diagnostic techniques involve anorectal manometry,[18] barium enema, and rectal biopsy. The Guidelines for diagnosis were decided in an International Consensus Conference and published in 2005. The suction rectal biopsy was considered the current gold standard in the diagnosis of Hirschsprung's disease.[19]
Radiologic findings may also assist with diagnosis.[20]
Treatment
Treatment of Hirschsprung's disease consists of surgical removal (resection) of the abnormal section of the colon, followed by reanastomosis. There used to be two steps typically used to achieve this goal.
Colostomy
- The first stage used to be a colostomy. When a colostomy is performed, the large intestine is cut and an opening is made through the abdomen. This allows bowel contents to be discharged into a bag.
- Later, when the child’s weight, age, and condition is right, a pull-through procedure is performed.
Swenson, Soave, Duhamel, and Boley procedures
Orvar Swenson, who discovered the cause of Hirschsprung’s, first performed it in 1948.[21] The pull-through procedure repairs the colon by connecting the functioning portion of the bowel to the anus. The pull-through procedure is the typical method for treating Hirschsprung’s in younger patients. Swenson devised the original procedure, and the pull-through surgery has been modified many times.
The first surgical treatment involving surgical resection followed by reanastomosis without a colostomy occurred as early as 1933 by Doctor Baird in Birmingham on a one year old boy.
The Swenson, Soave, Duhamel, and Boley procedures all vary slightly from each other:
- Swenson
- The Swenson procedure leaves a small portion of the diseased bowel.
- Soave
- The Soave procedure leaves the outer wall of the colon unaltered. The Boley procedure is a small modification of the Soave procedure. The term "Soave-Boley" procedure is sometimes used.[22][23]
- Duhamel
- The Duhamel procedure uses a surgical stapler to connect the good and bad bowel.
Of those 15% of children who do not obtain full control, other treatments are available. If constipation is the problem then usually laxatives or a high fiber diet will overcome the problem. If lack of control is the problem then a stoma may be necessary. The Malone antegrade colonic enema (ACE) is also an option.[24] This is where a tube goes through the abdominal wall to the appendix or, if available, to the colon. Then once a day the bowel is flushed.[25] Children as young as 6 do fine with administering this on their own. Details of ostomical sugery and its results can be found in the book Unwanted Baggage by Prosser.[26]
If the affected portion of the lower intestine is restricted to the lower portion of the rectum, other surgical procedures, such as the posterior rectal myectomy, can be performed. The prognosis is good in 70% of cases. Chronic post-operative constipation is present in 7%–8% of the operated cases. Post-operative enterocolites is a severe manifestation that is present in the 10%–20% of operated patients.
Associated syndromes
- Smith-Lemli-Opitz syndrome[27]
- Mowat-Wilson syndrome[28]
- MEN2[29]
- Bardet-Biedl syndrome
- Waardenburg syndrome
- Trisomy 21[30]
- Congenital central hypoventilation syndrome[31]
See also
- Intestinal Neuronal Dysplasia
- Achalasia
- Neonatal intensive care (NICU)
References
- ^ Parisi MA; Pagon, RA; Bird, TD; Dolan, CR; Stephens, K; Adam, MP (2002). Pagon RA, Bird TC, Dolan CR, Stephens K. ed. "Hirschsprung Disease Overview". GeneReviews. PMID 20301612.
- ^ Suita S, Taguchi T, Ieiri S, Nakatsuji T (2005). "Hirschsprung's disease in Japan: analysis of 3852 patients based on a nationwide survey in 30 years". Journal of Pediatric Surgery 40 (1): 197–201; discussion 201–2. doi:10.1016/j.jpedsurg.2004.09.052. PMID 15868585.
- ^ Hirschsprung's Disease and Allied Disorders. Berlin: Springer. 2007. ISBN 3-540-33934-5.
- ^ synd/1163 at Who Named It?
- ^ Hirschsprung, H. (1888). "Stuhlträgheit Neugeborener in Folge von Dilatation und Hypertrophie des Colons". Jahrbuch für Kinderheilkunde und physische Erziehung (Berlin) 27: 1–7.
- ^ Worman S, Ganiats TG (1995). "Hirschsprung's disease: a cause of chronic constipation in children". Am Fam Physician 51 (2): 487–94. PMID 7840044.
- ^ Martucciello G, Bicocchi MP, Dodero P.,Lerone M.,Silengo Cirillo M, Puliti A, Gimelli G, Romeo G. (1992). "Total colonic aganglionosis associated with interstitial deletion of the long arm of chromosome 10". Pediatric Surgery International 7 (4): 308–310. doi:10.1007/BF00183991.
- ^ Romeo G,Ronchetto P, Luo Y, Barone V, Seri M, Ceccherini I, Pasini B, Bocciardi R, Lerone M, Kääriäinen H & Martucciello G (1994). "Point mutations affecting the tyrosine kinase domain of the RET proto-oncogene in Hirschsprung's disease". Nature 367 (6461): 377–378. doi:10.1038/367377a0. PMID 8114938.
- ^ Angrist, Misha; Kauffman, Erick; Slaugenhaupt, Susan A.; Cox Matise, Tara; Puffenberger, Erik G.; Shaw Washington, Sarah; Lipson, Anthony; Cass, Daniel T. et al. (1993). "A gene for Hirschsprung disease (megacolon) in the pericentromeric region of human chromosome 10". Nat. Genet. 4 (4): 351–6. doi:10.1038/ng0893-351. PMID 8401581.
- ^ Lyonnet, S.; Bolino, A.; Pelet, A.; Abel, L.; Nihoul-Fékété, C.; Briard, M. L.; Mok-Siu, V.; Kaariainen, H. et al. (1993). "A gene for Hirschsprung disease maps to the proximal long arm of chromosome 10". Nat. Genet. 4 (4): 346–50. doi:10.1038/ng0893-346. PMID 8401580.
- ^ Kays DW (1996). "Surgical conditions of the neonatal intestinal tract". Clinics in Perinatology 23 (2): 353–75. PMID 8780909.
- ^ Colwell, Janice (2004). Fecal and Urinary Diversion Management. Mosby. pp. 264. ISBN 978-0-323-02248-4.
- ^ Goldberg EL (1984). "An epidemiological study of Hirschsprung's disease". Int J Epidemiol 13 (4): 479–85. doi:10.1093/ije/13.4.479. PMID 6240474.
- ^ Online 'Mendelian Inheritance in Man' (OMIM) 142623
- ^ Martucciello, G; Ceccherini, I; Lerone, M; Jasonni, V (2000). "Pathogenesis of Hirschsprung's disease". Journal of Pediatric Surgery 35 (7): 1017–1025. doi:10.1053/jpsu.2000.7763. PMID 10917288.
- ^ Puri P, Shinkai T (2004). "Pathogenesis of Hirschsprung's disease and its variants: recent progress". Semin. Pediatr. Surg. 13 (1): 18–24. doi:10.1053/j.sempedsurg.2003.09.004. PMID 14765367.
- ^ Dobbins, W. O.; Bill, A. H. (1965). "Diagnosis of Hirschsprung's Disease Excluded by Rectal Suction Biopsy". New England Journal of Medicine 272 (19): 990–993. doi:10.1056/NEJM196505132721903. PMID 14279253. edit
- ^ Eli Ehrenpreis (October 2003). Anal and rectal diseases explained. Remedica. pp. 15–. ISBN 978-1-901346-67-1. http://books.google.com/books?id=nB-HLHPaxu0C&pg=PA15. Retrieved 10 November 2010.
- ^ Martucciello G, Pini Prato A, Puri P, Holschneider AM, Meier-Ruge W, Tovar JA, Grosfeld JL. (2005). "Controversies concerning diagnostic guidelines for anomalies of the enteric nervous system: a report from the fourth International Symposium on Hirschsprung's disease and related neurocristopathies". J Pediatr Surg. 40 (10): 1527–31. doi:10.1016/j.jpedsurg.2005.07.053. PMID 16226977.
- ^ Kim, H. J.; Kim, A. Y.; Lee, C. W.; Yu, C. S.; Kim, J.-S.; Kim, P. N.; Lee, M.-G.; Ha, H. K. (2008). "Hirschsprung disease and hypoganglionosis in adults: radiologic findings and differentiation". Radiology 247 (2): 428–34. doi:10.1148/radiol.2472070182. PMID 18430875.
- ^ Swenson O (1989). "My early experience with Hirschsprung's disease". J. Pediatr. Surg. 24 (8): 839–44; discussion 844–5. doi:10.1016/S0022-3468(89)80549-4. PMID 2671336.
- ^ W. Allan Walker (1 July 2004). Pediatric gastrointestinal disease: pathophysiology, diagnosis, management. PMPH-USA. pp. 2120–. ISBN 978-1-55009-240-0. http://books.google.com/books?id=dI5NhvRaWbkC&pg=PA2120. Retrieved 10 November 2010.
- ^ Timothy R. Koch (2003). Colonic diseases. Humana Press. pp. 387–. ISBN 978-0-89603-961-2. http://books.google.com/books?id=OUDJ8Vr4ZrgC&pg=PA387. Retrieved 10 November 2010.
- ^ Malone PS, Ransley PG, Kiely EM. (1990). "Preliminary report: the antegrade continence enema". Lancet 336 (8725): 1217–1218. PMID 1978072me=336.
- ^ Walsh, Koyle, Waxman (2000). "The Malone ACE Procedure for Fecal Incontinence". Infections in Urology 13 (4). http://www.medscape.com/viewarticle/410216_4.
- ^ Elizabeth And Philip Prosser; Philip Prosser (10 February 2011). Unwanted Baggage: A Comprehensive Introduction Surgical Ostomies. AuthorHouse. ISBN 978-1-4567-7155-3. http://books.google.com/books?id=BpbQADFcXogC. Retrieved 20 May 2012.
- ^ Mueller, C.; Patel, S.; Irons, M.; Antshel, K.; Salen, G.; Tint, G.S.; Bay, C. (2003). "Normal cognition and behavior in a Smith-Lemli-Opitz syndrome patient who presented with Hirschsprung disease". American Journal of Medical Genetics. Part a 123A (1): 100–6. doi:10.1002/ajmg.a.20491. PMC 1201564. PMID 14556255. //www.ncbi.nlm.nih.gov/pmc/articles/PMC1201564/.
- ^ Bonnard, Arnaud; Zeidan, Smart; Degas, Vanessa; Viala, Jérome; Baumann, Clarisse; Berrebi, Dominique; Perrusson, Odile; El Ghoneimi, Alaa (2009). "Outcomes of Hirschsprung's disease associated with Mowat-Wilson syndrome". Journal of Pediatric Surgery 44 (3): 587–91. doi:10.1016/j.jpedsurg.2008.10.066. PMID 19302864.
- ^ Saunders CJ, Zhao W, Ardinger HH (2009). "Comprehensive ZEB2 gene analysis for Mowat-Wilson syndrome in a North American cohort: a suggested approach to molecular diagnostics". American Journal of Medical Genetics. Part a 149A (11): 2527–31. doi:10.1002/ajmg.a.33067. PMID 19842203.
- ^ Flori, Elisabeth; Girodon, Emmanuelle; Samama, Brigitte; Becmeur, François; Viville, Brigitte; Girard-Lemaire, Françoise; Doray, Bérénice; Schluth, Caroline et al. (2005). "Trisomy 7 mosaicism, maternal uniparental heterodisomy 7 and Hirschsprung's disease in a child with Silver-Russell syndrome". European Journal of Human Genetics 13 (9): 1013–8. doi:10.1038/sj.ejhg.5201442. PMID 15915162.
- ^ De Pontual, L.; Pelet, A.; Clement-Ziza, M.; Trochet, D.; Antonarakis, S.E.; Attie-Bitach, T.; Beales, P.L.; Blouin, J.-L. et al. (2007). "Epistatic interactions with a common hypomorphic RET allele in syndromic Hirschsprung disease". Human Mutation 28 (8): 790–6. doi:10.1002/humu.20517. PMID 17397038.
External links
- [1]
- Hirschsprung's disease at the Open Directory Project
- Ostomy | Stomas – Ostomy | Ostomy Diet | Ostomy Products | Ostomy Benefits | Ostomy Help
Congenital malformations and deformations of digestive system (Q35–Q45, 749–751)
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Upper GI tract |
Tongue, mouth and pharynx
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Cleft lip and palate · Van der Woude syndrome · tongue (Ankyloglossia, Macroglossia, Hypoglossia)
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Esophagus
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EA/TEF (Esophageal atresia: types A, B, C, and D, Tracheoesophageal fistula: types B, C, D and E)
esophageal rings (Esophageal web · upper, Schatzki ring · lower)
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Stomach
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Pyloric stenosis · Hiatus hernia
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Lower GI tract |
Intestines
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Intestinal atresia (Duodenal atresia) · Meckel's diverticulum · Hirschsprung's disease · Intestinal malrotation · Dolichocolon · Enteric duplication cyst
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Rectum/anal canal
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Imperforate anus · Persistent cloaca
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Accessory |
Pancreas
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Annular pancreas · Accessory pancreas · Johanson–Blizzard syndrome
Pancreas divisum
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Bile duct
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Choledochal cysts (Caroli disease) · Biliary atresia
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Liver
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Alagille syndrome · Polycystic liver disease
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noco/cofa(c)/cogi/tumr, sysi
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anat(t, g, p)/phys/devp/enzy
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noco/cong/tumr, sysi/epon
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proc, drug(A2A/2B/3/4/5/6/7/14/16), blte
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Extracellular ligand disorders
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Cytokine |
EDA Hypohidrotic ectodermal dysplasia · Camurati-Engelmann disease
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Ephrin |
Craniofrontonasal syndrome
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WNT |
Tetra-amelia syndrome
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TGF |
OFC 11
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Fas ligand |
Autoimmune lymphoproliferative syndrome 1B
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Endothelin |
EDN3 (Waardenburg syndrome IVb, Hirschsprung's disease 4)
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Other |
DHH (DHH XY gonadal dysgenesis) · BMP15 (Premature ovarian failure 4) · TSHB (Congenital hypothyroidism 4)
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see also intercellular signaling peptides and proteins
B structural (perx, skel, cili, mito, nucl, sclr) · DNA/RNA/protein synthesis (drep, trfc, tscr, tltn) · membrane (icha, slcr, atpa, abct, othr) · transduction (iter, csrc, itra), trfk
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Genetic disorder, membrane: cell surface receptor deficiencies
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G protein-coupled receptor
(including hormone) |
Class A |
- TSHR (Congenital hypothyroidism 1)
- LHCGR (Male-limited precocious puberty)
- FSHR (XX gonadal dysgenesis)
- EDNRB (ABCD syndrome, Waardenburg syndrome 4a, Hirschsprung's disease 2)
- AVPR2 (Nephrogenic diabetes insipidus 1)
- PTGER2 (Aspirin-induced asthma)
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Class B |
- PTH1R (Jansen's metaphyseal chondrodysplasia)
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Class C |
- CASR (Familial hypocalciuric hypercalcemia)
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Class F |
- FZD4 (Familial exudative vitreoretinopathy 1)
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Enzyme-linked receptor
(including
growth factor) |
RTK |
- ROR2 (Robinow syndrome)
- FGFR1 (Pfeiffer syndrome, KAL2 Kallmann syndrome)
- FGFR2 (Apert syndrome, Antley-Bixler syndrome, Pfeiffer syndrome, Crouzon syndrome, Jackson-Weiss syndrome)
- FGFR3 (Achondroplasia, Hypochondroplasia, Thanatophoric dysplasia, Muenke syndrome)
- INSR (Donohue syndrome
- Rabson–Mendenhall syndrome)
- NTRK1 (Congenital insensitivity to pain with anhidrosis)
- KIT (KIT Piebaldism, Gastrointestinal stromal tumor)
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STPK |
- AMHR2 (Persistent Mullerian duct syndrome II)
- TGF beta receptors: Endoglin/Alk-1/SMAD4 (Hereditary hemorrhagic telangiectasia)
- TGFBR1/TGFBR2 (Loeys-Dietz syndrome)
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GC |
- GUCY2D (Leber's congenital amaurosis 1)
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JAK-STAT |
- Type I cytokine receptor: GH (Laron syndrome)
- CSF2RA (Surfactant metabolism dysfunction 4)
- MPL (Congenital amegakaryocytic thrombocytopenia)
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TNF receptor |
- TNFRSF1A (TNF receptor associated periodic syndrome)
- TNFRSF13B (Selective immunoglobulin A deficiency 2)
- TNFRSF5 (Hyper-IgM syndrome type 3)
- TNFRSF13C (CVID4)
- TNFRSF13B (CVID2)
- TNFRSF6 (Autoimmune lymphoproliferative syndrome 1A)
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Lipid receptor |
- LRP: LRP2 (Donnai-Barrow syndrome)
- LRP4 (Cenani Lenz syndactylism)
- LRP5 (Worth syndrome, Familial exudative vitreoretinopathy 4, Osteopetrosis 1)
- LDLR (LDLR Familial hypercholesterolemia)
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Other/ungrouped |
- Immunoglobulin superfamily: AGM3, 6
- Integrin: LAD1
- Glanzmann's thrombasthenia
- Junctional epidermolysis bullosa with pyloric atresia
EDAR (EDAR Hypohidrotic ectodermal dysplasia)
- PTCH1 (Nevoid basal cell carcinoma syndrome)
- BMPR1A (BMPR1A Juvenile polyposis syndrome)
- IL2RG (X-linked severe combined immunodeficiency)
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- See also
- cell surface receptors
B structural (perx, skel, cili, mito, nucl, sclr) · DNA/RNA/protein synthesis (drep, trfc, tscr, tltn) · membrane (icha, slcr, atpa, abct, othr) · transduction (iter, csrc, itra), trfk
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