Purpose: To identify the disease-causing mutations in two large Bulgarian Romani (Gypsy) pedigrees: one with autosomal dominant retinitis pigmentosa (adRP) with partial penetrance and the other with severe X-linked RP (xlRP). Methods: Detailed clinical investigations were undertaken and genomic DNA was extracted from blood samples. DNA was analyzed by PCR amplification with gene-specific primers and direct genomic sequencing. Results: Analysis of the complete coding sequence of PRPF31 in the adRP family led to the identification of a new heterozygous splice site mutation IVS6+ 1G> T. RPGR mutation screening in affected male individuals in the X-linked RP family identified a hemizygous c. ORF15+ 652_653delAG mutation. Interestingly this mutation was found in a homozygous state in one severely affected female from the family.

Conclusions: In this first report of molecular genetic analysis of retinitis pigmentosa in Romani families, we describe a novel PRPF31 mutation and present the first case of a homozygous mutation in the RPGR gene in a female individual.