COACH syndrome is an autosomal recessive disorder characterized by impaired intellectual development, ataxia due to cerebellar hypoplasia, and hepatic fibrosis. Other features, such as coloboma and renal cysts, may be variable. COACH syndrome is considered by some to be a subtype of Joubert syndrome (JBTS; see 213300) with congenital hepatic fibrosis. Identification of liver disease in these patients is critical because some may develop complications such as portal hypertension with fatal variceal bleeding (Brancati et al., 2009; Doherty et al., 2010).
Genetic Heterogeneity of COACH Syndrome
Also see COACH syndrome-2 (COACH2; 619111), caused by mutation in in the CC2D2A gene (612013), and COACH syndrome-3 (COACH3; 619113), caused by mutation in the RPGRIP1L gene (610937).
Most cases of COACH syndrome are caused by mutation in the TMEM67 gene. [from
OMIM]