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An inherited syndrome characterized by the combination of hepatic fibrosis, early onset ataxia, cerebellar aplasia, oligophrenia, and coloboma. COACH is an acronym for cerebellar vermis aplasia, oligophrenia, congenital ataxia, ocular coloboma and hepatic fibrosis.

Fewer than 20 cases have been described. Autosomal recessive inheritance. Parental consanguinity has been reported in some cases.

The diagnosis is based on moderate mental retardation associated with early-onset ataxia and hypotonia, inconstant coloboma, and hepatic cirrhosis in association with a positive family history. Imaging studies show cerebellar vermis hypoplasia or aplasia but normal supratentorial structures. Liver biopsy characteristically reveals periportal fibrosis, cholestasis, reduced number of intrahepatic bile ducts, and chronic inflammatory infiltrates. Other features may involve the head and neck (flat round face, hypertelorism, ptosis, optic nerve coloboma and optic disc atrophy, upturned nose, macrostomia, macroglossia, occipital encephalocele), the central nervous system (ataxia and hypotonia, later spasticity; the term “molar tooth” sign is used to describe the brainstem malformation with elongated superior cerebellar peduncles and pronounced interpeduncular fossa), the musculoskeletal system (postaxial polydactyly, slender skeleton), the kidneys (multiple medullary cysts, renal impairment), and the viscera (hepatomegaly splenomegaly, hepatic cirrhosis, and portal hypertension in 70% of patients). Episodic tachypnea and ventricular septal defect have been described. Death may result from complications of hepatic fibrosis, gastrointestinal bleeding, or kidney failure. Successful liver and combined liver and kidney transplantation have been reported.

Obtain a complete blood count (anemia secondary to gastrointestinal hemorrhage) and check serum levels of electrolytes. Thrombocytopenia secondary to portal hypertension with splenomegaly (hypersplenism) was described in one patient. Assess renal (creatinine, blood urea nitrogen) and hepatic function (transaminases, bilirubin, albumin, coagulation status). Reduced doses of muscle relaxant agents may be required. Consider alterations in the metabolism and elimination of drugs in the presence of hepatic and/or renal failure. The potential for airway obstruction, a result of macroglossia, requires preoperative evaluation. Careful insertion of nasogastric tubes is required because the majority of patients have esophageal varices. Bleeding from abdominal surgery may be increased in the presence of portal hypertension and coagulopathy. Large-bore intravenous access is therefore recommended. Consider subacute bacterial endocarditis prophylaxis in the presence of congenital cardiac lesions.

Joubert Syndrome: A genetic peroxisomal disorder characterized by cerebral malformations (vermis and brainstem) resulting in severe coordination (ataxia) and breathing (sleep apnea, hyperpnea) disorders.

Arima Syndrome (Cerebro-Oculo-Hepato-Renal Syndrome): This syndrome is similar to Joubert syndrome, however, the Arima syndrome also presents with retinal dystrophy and visual tracking anomalies (oculomotor ataxia), renal failure, and liver dysfunction.

Loken Senior Syndrome: An autosomal recessive inherited disorder characterized by rapidly progressive renal insufficiency (nephronophthisis), progressive retinitis pigmentosa, and ataxia. Manifestation during the first year of life. Blindness develops within the first 2 years of life.

Renal-Coloboma Syndrome: A familial syndrome combining ocular, renal, and neurologic anomalies.

Foell D, August C, Frosch M, et al: Early ...

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