Abstract
Abstract: :
Purpose: To screen for mutations in genes that may be responsible for retinal dystrophies in the DNA of Turkish patients. Methods: Forty families from different parts of Turkey affected with retinitis pigmentosa were collected and the genomic DNA of their members was isolated for molecular studies. The pedigrees were drawn with information obtained from family members and analysed to determine the genetic inheritance of the disease.We used both haplotyping and SSCP techniques to screen for mutations in the genes encoding rhodopsin, the alpha and beta subunits of cGMP-phosphodiesterase (PDEA and PDEB, respectively ) and RPE65. Results: A high incidence of consanguinity ( 55% ) was observed in Turkish families with retinitis pigmentosa. Twenty eight of 40 families investigated had autosomal recessive inheritance ( 70% ), ten of them were simplex ( 25% ), and two families had autosomal dominant disease ( 5% ). With the use of haplotype analysis we were able to exclude the PDEA, PDEB and RPE 65 genes as the cause of disease in the families studied. We did not find either any disease causing mutations in the rhodopsin gene of these patients after SSCP screening of the rhodopsin exons. Conclusion: Autosomal recessive inheritance and consanguinity are the most common features of Turkish patients with retinitis pigmentosa. None of the genes we screened known to cause different forms of this disease are mutated in the families studied. We are currently investigating other genes that may be responsible for the retinal degeneration of these Turkish patients.
Keywords: 554 retina • 562 retinal degenerations: hereditary • 568 retinitis