Potential Founder Effect of Tyrosinase Gene Mutations in Oculocutaneous Albinism Families fromWest of Iran

Background: Non syndromic oculocutaneous albinism type (OCA) is caused by mutations in tyrosinase (TYR), OCA۲, TYRP۱, MATP(SLC۴۵A۲), SLC۲۴A۵ and C۱۰ORF۱۱ genes. Screening for mutations is important in families with oculocutaneous albinism patients inorder to accurately diagnose the albinism type, genetic counseling and future therapeutic purposes.Objectives: The Aim of this study was to investigate the founder effect of most frequent mutations in OCA patients.Methods: TYR gene was sequenced in ۲۶ unrelated inbred OCA families as well as ۵۶ unrelated healthy individuals. In addition, homozygositymapping was performed using ۱۳ STR markers for ۶ OCA loci (TYR, OCA۲, TYRP۱, MATP (SLC۴۵A۲), SLC۲۴A۵ and C۱۰ORF۱۱genes). Different mutations were found in these genes from which a single base duplication (c.۲۸۶dupA) and two single base substitutionsc.۹۹۶G > A (p.M۳۳۲I) and c.۲۳۰G > A (p.R۷۷Q) had the most frequencies among the OCA families. In order to investigatethe founder effect of these mutations, the haplotypes of two STR markers (TYR-S۱ and TYR-S۲) inside the TYR gene were ascertained.Results: It was revealed that families with similar mutation harbored similar haplotype for the TYR STR markers too.Conclusions: We conclude that these mutations are possible founder mutations in the Iranian population.

Keywords:

OCA , TYR , Capillary Electrophoresis , Founder Effect