A NOVEL MUTATION IN TRP1 GENE IN AN OCULAR CUTANEOUS ALBINISM PATIENT

Purpose: To elucidate the molecular genetics defect of ocular cutaneous albinism. Methods: One member of a family affected with ocular cutaneous albinism was studied to characterize the clinical phenotype and identify the disease-causing mutation. The family members were examined with ophthalmoscopy, electroretinography, and Goldmann perimetry. Clinical features comprises congenital nystagmus, iris transillumination, foveal hypoplasia and fundus hypopgmentation. The complete coding sequence of the TRP1 gene, on chromosome 9, including the exon-intron boundaries, was amplified by PCR (polymerase chain reaction). Direct DNA sequencing analysis was performed and compared to TRP1 consensus sequences obtained from the National Centre for Biotechnology Information (NCBI). Results: This analysis revealed a novel homozygous missense mutation, c.G869A on exon 4. This nucleotide variation leads to the aminoacid change cysteine to tyrosine (p.C290Y). Conclusions: The lack of this variation on 50 healthy controls assessed by dHPLC analysis, confirmed that this protein change is likely the cause of the albino phenotype present in this patient