Tay-Sachs Disease (TSD) falls into which type of inheritance?

• A. X-Linked Recessive
• B. Autosomal Recessive
• C. Autosomal Dominant
• D. Mitochondrial Inheritance

Answer: (B)

Tay-Sachs Disease (TSD) is classified as an autosomal recessive disorder. This means that for an individual to express Tay-Sachs, they must inherit two copies of the defective gene—one from each parent. The gene responsible for Tay-Sachs is found on chromosome 15 and encodes an enzyme called Hexosaminidase A. When both copies of the gene are mutated, the enzyme is deficient, leading to the accumulation of GM2 gangliosides in the nerve cells, which causes the neurological symptoms associated with the disease.

In the case of autosomal recessive inheritance, individuals with only one copy of the mutated gene (carriers) do not exhibit any symptoms and typically have normal enzyme activity. This pattern of inheritance is characteristic of many genetic conditions where a recessive allele must be present in two copies to express the phenotype. Thus, because Tay-Sachs Disease requires two recessive alleles for its manifestation, it is correctly classified under autosomal recessive inheritance.