Case report of albinism in an Iranian non-consanguineous family due to compound heterozygosity

Introduction:Oculocutaneous albinism (OCA) is heterogeneous group of inherited disorders characterized by defective melanin biosynthesis in the skin, hair, and/or eyes. OCA1, the most common and severe form, is inherited in AR manner, and caused by mutations in the tyrosinase (TYR) gene. Although the clinical phenotype of different types of OCA is not always distinguishable, because of mutations in different genes, making molecular diagnosis is useful tool and essential for genetic counseling.• Casereport: This study was designed to find the genetic defect in years-old affected girl with white hair, skin, blue irides since birth, refractive error and strabismus. She has non-consanguineous apparently normal parents, who wanted to know about etiology, recurrence risk and possibly prevention method for their later pregnancies. During genetic counseling there was family history of albinism. The child father had an aunt and by chance the child mother also had grandfather, who both were albinos. Using NGS and checking the known disease classic OCA gene candidates on DNA from her blood sample, two mutations were detected in TYR gene, were confirmed by sanger sequencing. Sanger Sequencing of the TYR gene, then was performed for her parents. Her mother and father were determined consequently heterozygote for those mutations.• Discussion Conclusion:The affected girl is compound heterozygote for two different pathogenic variant in TYR gene. The identified c.308G> p.C103S) missense mutation has not been reported previously, while the other c.1255G> (p.G419R) has been already reported .According to compound heterozygosity of the proband for Albinism, as an AR disorder, and her parents heterozyosity, there is 25% recurrence risk. Knowing these two mutations, they can use preimplantation genetic diagnosis (PGD) to assure the embryos implanted are not affected, or use prenatal diagnosis. Genetic counseling and carrier detection is also recommended for all high-risk individuals in this family.

کلیدواژه ها:

albinism ، compound heterozygote ، TYR gene AR