Clinical and Molecular Findings of Nine Cases with Tay- Sachs Disease From Turkiye

Abstract

Objective: Tay-Sachs disease is a fatal inherited lysosomal storage disease that mostly has an early infantile onset. We presented a case series of Tay-Sachs disease, describe the clinical and molecular findings, and compare the genetic spectrum with previously reported mutations from Turkiye.Methods: Patients with Tay-Sachs disease who were referred to the Istanbul University, Istanbul Faculty of Medicine, Department of Medical Genetics between January 2016 and December 2021 were included in this study. The diagnosis was confirmed by determining the level of serum 0-hexosaminidase activity and the detection of a biallelic related variant upon Sanger sequencing of the HEXA gene. The clinical and molecular findings of nine cases were re-evaluated. Results: Three disease-causing variants in the HEXA gene including c.78G>A (p.(Trp26Ter)) in three cases, c.1177C>T (p.(Arg393Ter)) in two cases, and c.1100_1111del (p.(Gly367_Tyr370del)) in three cases were determined. Moreover, a novel c.786C>G (p.(His262Gln)) variant was detected in one case. All of the stated variants were identified in the homozygous state.Conclusion: Our study both reassessed and expanded the known mutation spectrum of Tay-Sachs disease in Turkiye. Given the expanding horizon of newborn screening and population carrier testing, understanding the spectrum of population-specific disease-causing variants will facilitate early diagnosis of patients and carriers.