How is Tay-Sachs disease inherited?

Tay-Sachs disease is a genetic disorder caused by a deficiency in the enzyme Hexosaminidase A, which leads to the accumulation of GM2 gangliosides in the nerve cells. This condition is inherited in an autosomal recessive manner, meaning that both copies of the gene in an individual must be mutated for the disease to manifest. In the case of Tay-Sachs, both parents must be carriers of the mutated gene, and when two carriers have a child, there is a 25% chance that the child will inherit the condition.

In autosomal recessive inheritance, individuals who have one normal and one mutated copy of the gene (carriers) typically do not show symptoms of the disease but can pass the mutated gene to their offspring. Therefore, Tay-Sachs disease presents predominantly in children when both parents are carriers, leading to a significant risk for affected children where both alleles of the gene are non-functional. This pattern of inheritance distinguishes Tay-Sachs from other inheritance types, reinforcing the understanding of genetic transmission in human hereditary conditions.