Epstein syndrome

Epstein syndrome is a rare genetic disease caused by a mutation in the MYH9 gene, which codes for nonmuscle myosin heavy chain IIA. It affects the kidneys and can lead to kidney failure. The condition was first recognised in 1972 when two families showed symptoms resembling Alport syndrome, and it was later distinguished from other MYH9-related disorders such as May-Hegglin anomaly, Sebastian syndrome and Fechtner syndrome by its link to a mutation at the R702 codon. The mutation is inherited in an autosomal dominant pattern, although sporadic cases occur. Early signs are a tendency to bleed, with nosebleeds and purpura, together with a low count of unusually large platelets, called macrothrombocytopenia. Other features include protein in the urine, sensorineural hearing loss, nephritis and cataracts. Most patients develop nephritis in childhood and progress to kidney failure in adolescence, though severity varies between patients. The large platelets are poor at binding to each other to seal damaged vessels, which explains the bleeding. Diagnosis rests on finding giant platelets on a peripheral blood smear and examining white cell inclusions.