Tay-Sachs disease is inherited in which pattern?

• A. Autosomal recessive
• B. Autosomal dominant
• C. X-linked recessive
• D. Mitochondrial

Answer: (A)

Tay-Sachs disease is inherited in an autosomal recessive pattern, meaning two mutated copies of the HEXA gene are needed for the disease to occur. When both parents are carriers, each child has a 25% chance of being affected, a 50% chance of being a carrier, and a 25% chance of being unaffected. Carriers typically show no symptoms because one functioning copy of hexosaminidase A is usually enough to prevent buildup of GM2 ganglioside. The condition affects males and females equally and isn’t inherited through the X chromosome or mitochondria, which would produce different transmission patterns. The disease results from hexosaminidase A deficiency, leading to GM2 ganglioside accumulation in neurons and rapid neurodegeneration in infancy, with higher carrier frequencies in populations such as Ashkenazi Jews.