Homozygous p.R284* mutation in HEXB gene causing Sandhoff disease with nystagmus.

Sandhoff disease is a rare, genetic, lipid storage disorder characterized by progressive degeneration of the nerve cells (neurons) in the brain and spinal cord. This disease is caused by mutations in the beta-hexosaminidase beta-subunit (HEXB) gene. Here, we investigated the clinical characteristics and molecular basis of Sandhoff disease in an infant female patient from Jordan. The initial sign was nystagmus, which was noted at birth. To our knowledge, this is the first report of Sandhoff disease from Jordan. Introducing lysosomal enzyme assays to the testing of children with global developmental delay with unknown etiology in countries with high rates of consanguinity will not only increase the percentage of diagnosed cases, but will also help orient genetic counseling and prenatal diagnosis and eventually will reduce the overall burden of disabilities in these countries.