What is (are) COACH syndrome ?
COACH syndrome is a condition that mainly affects the brain and liver.  Most individuals with COACH syndrome have mental retardation, liver problems (fibrosis), and difficulty with movement (ataxia).  Some may also have an abnormality of the eye (called a coloboma) or abnormal eye movements (such as nystagmus).  This condition is inherited in an autosomal recessive manner; 70% of cases are thought to be caused by mutations in the TMEM67 gene.  COACH syndrome is considered a rare form of another condition, Joubert syndrome.