Founder mutation causing infantile GM1-gangliosidosis in the Gypsy population.

The Gypsies are a trans-national founder population of Asian descent, whose genetic heritage is still incompletely characterized. Here, we describe the first founder mutation leading to a lysosomal storage disorder in this population: R59H in GLB1, which causes infantile GM1-gangliosidosis. The R59H carrier rate is approximately 2% in the general Gypsy population and approximately 10% in the Rudari sub-isolate. Haplotype analysis suggests that the Gypsy diaspora may have contributed to the spread of this mutation to South America.