From HPO
Aganglionic megacolon- MedGen UID:
- 5559
- •Concept ID:
- C0019569
- •
- Disease or Syndrome
The disorder described by Hirschsprung (1888) and known as Hirschsprung disease or aganglionic megacolon is characterized by congenital absence of intrinsic ganglion cells in the myenteric (Auerbach) and submucosal (Meissner) plexuses of the gastrointestinal tract. Patients are diagnosed with the short-segment form (S-HSCR, approximately 80% of cases) when the aganglionic segment does not extend beyond the upper sigmoid, and with the long-segment form (L-HSCR) when aganglionosis extends proximal to the sigmoid (Amiel et al., 2008). Total colonic aganglionosis and total intestinal HSCR also occur.
Genetic Heterogeneity of Hirschsprung Disease
Several additional loci for isolated Hirschsprung disease have been mapped. HSCR2 (600155) is associated with variation in the EDNRB gene (131244) on 13q22; HSCR3 (613711) is associated with variation in the GDNF gene (600837) on 5p13; HSCR4 (613712) is associated with variation in the EDN3 gene (131242) on 20q13; HSCR5 (600156) maps to 9q31; HSCR6 (606874) maps to 3p21; HSCR7 (606875) maps to 19q12; HSCR8 (608462) maps to 16q23; and HSCR9 (611644) maps to 4q31-q32.
HSCR also occurs as a feature of several syndromes including the Waardenburg-Shah syndrome (277580), Mowat-Wilson syndrome (235730), Goldberg-Shprintzen syndrome (609460), and congenital central hypoventilation syndrome (CCHS; 209880).
Whereas mendelian modes of inheritance have been described for syndromic HSCR, isolated HSCR stands as a model for genetic disorders with complex patterns of inheritance. Isolated HSCR appears to be of complex nonmendelian inheritance with low sex-dependent penetrance and variable expression according to the length of the aganglionic segment, suggestive of the involvement of one or more genes with low penetrance. The development of surgical procedures decreased mortality and morbidity, which allowed the emergence of familial cases. HSCR occurs as an isolated trait in 70% of patients, is associated with chromosomal anomaly in 12% of cases, and occurs with additional congenital anomalies in 18% of cases (summary by Amiel et al., 2008).
Sensorineural hearing loss disorder- MedGen UID:
- 9164
- •Concept ID:
- C0018784
- •
- Disease or Syndrome
A type of hearing impairment in one or both ears related to an abnormal functionality of the cochlear nerve.
Premature graying of hair- MedGen UID:
- 75524
- •Concept ID:
- C0263498
- •
- Finding
Development of gray hair at a younger than normal age.
White forelock- MedGen UID:
- 91023
- •Concept ID:
- C0344312
- •
- Finding
A triangular depigmented region of white hairs located in the anterior midline of the scalp.
Hypopigmented skin patches- MedGen UID:
- 373164
- •Concept ID:
- C1836735
- •
- Finding
White eyelashes- MedGen UID:
- 332275
- •Concept ID:
- C1836736
- •
- Finding
White color (lack of pigmentation) of the eyelashes.
White eyebrow- MedGen UID:
- 373165
- •Concept ID:
- C1836737
- •
- Finding
White color (lack of pigmentation) of the eyebrow.
Heterochromia iridis- MedGen UID:
- 98395
- •Concept ID:
- C0423318
- •
- Finding
Heterochromia iridis is a difference in the color of the iris in the two eyes.
Blue irides- MedGen UID:
- 108297
- •Concept ID:
- C0578626
- •
- Finding
A markedly blue coloration of the iris.
- Abnormality of the digestive system
- Abnormality of the eye
- Abnormality of the integument
- Ear malformation