No abstract

Tay-Sachs disease (TSD) is an autosomal recessive neurodegenerative disorder. It results from pathogenic variants in the HEXA gene that lead to deficient activity of the lysosomal β-hexosaminidase A enzyme (HEXA). HEXA consists of an α and a β subunit, encoded by the HEXA and the HEXB gene, respectively. When a patient is homozygous for a HEXA pathogenic variant, GM2 gangliosides are not hydrolyzed, accumulate in neuronal lysosomes and trigger progressive neuronal dysfunction, which begins around 2-6 months of age for infantile TSD and leads to complete disability and death, usually by 3-5 years of age (Gravel et al., 2001; Kaback & Desnick, 2001; Sutton, 2002). A diagnosis of infantile TSD is usually made before a child's third birthday on the basis of absent or significantly reduced level of HEXA activity measured through biochemical testing (Kaback & Desnick, 2001). Molecular analysis can confirm