What is the inheritance pattern of Tay Sachs disease in Ashkenazi Jews?

Tay Sachs disease is inherited in an autosomal recessive pattern, meaning that a child must inherit two copies of the defective gene—one from each parent—to develop the condition. Ashkenazi Jews are particularly noted for having a higher carrier frequency for the genetic mutation responsible for Tay Sachs disease due to a relatively high prevalence of the disease within this population.

In autosomal recessive disorders, carriers (who possess one copy of the mutated gene and one normal gene) typically do not exhibit symptoms of the disease, but they can pass the mutated gene to their offspring. When both parents are carriers of the Tay Sachs gene, there is a 25% chance with each pregnancy that their child will inherit both defective genes and, therefore, express the disease.

This inheritance pattern has important implications for genetic counseling, particularly in populations with a higher incidence of certain genetic disorders. In the case of Tay Sachs, screening for carriers and prenatal testing can help in making informed reproductive choices. The other genetic patterns listed do not apply to Tay Sachs disease, as it does not follow X-linked dominant, autosomal dominant, or mitochondrial inheritance.