Heimler syndrome

Heimler syndrome is a rare autosomal recessive condition whose defining features are sensorineural hearing loss, enamel hypoplasia of the secondary teeth (amelogenesis imperfecta), nail abnormalities and, in some people, retinal pigmentation changes that may appear only late in life. It is caused by mutations in the PEX1 or PEX6 genes, which take part in building peroxisomes, small cell compartments that handle fats and other metabolic tasks. Diagnosis is made on clinical grounds and confirmed by gene sequencing. No specific treatment is known, but the condition tends to produce only mild abnormalities and life expectancy is normal. Precise prevalence is not known, though it appears to be fewer than one in a million people. The condition was first described in 1991.