Carrier Rates of Four Single-Gene Disorders in Croatian Bayash Roma

Abstract

To assess how specific population history, different migration routes, isolation, and endogamy practices contributed to the distribution of several rare diseases found in specific Roma groups, we conducted a populationbased research study of rare disease mutations in Croatian Vlax Roma. We tested a total of 427 subjects from Baranja and MeCimurje for the presence of four mutations causing hereditary motor and sensory neuropathy type Lom (HMSNL), GM1 gangliosidosis (GM1), congenital cataracts, facial dysmorphism and neuropathy (CCFDN), and limb girdle muscle dystrophy type 2C (LGMD2C), using the RFLP-PCR method to estimate carrier frequencies. We identified a total of four individuals heterozygous for the mutation causing HMSNL in the Baranja population, with a carrier rate amounting to 1.5%. Carriers for other three mutations causing GM1, CCFDN, and LGMD2C were not found in our sample. The carrier rate for the HMSNL mutation in Baranja is lower than in other Vlax Roma groups. In addition, distinct differences in carrier rates between the Croatian Vlax groups point to different genetic history, despite their belonging to the same Roma migration category and subgroup. The difference in carrier rates is either the result of admixture or the reflection of a greater extent of genetic drift since recent founding, maintained by a high degree of endogamy.

Characterization of ADME genes variation in Roma and 20 populations worldwide

“…Their pronounced genetic differences from the majority Croatian population and traces of their ancestral origins have been detected in mitochondrial DNA [ 22 ], Y chromosome markers [ 23 , 24 ] and various autosomal common [ 25 ] and rare disease loci [ 26 ]. The recent study of ADME gene's CYP2B6 polymorphisms proved the distinctive position of the Croatian Roma in the world's populational variability [ 27 ] and indicated the need for a systematic investigation of the most important pharmacogenes' variants in the Roma.…”