Which condition is commonly inherited in an autosomal recessive pattern?

• A. Huntington disease
• B. Cystic fibrosis
• C. Sickle cell disease
• D. Tay-Sachs disease

Answer: (B)

Autosomal recessive inheritance means you must inherit two mutated copies of a gene to express the disease, and individuals with one mutated copy are usually healthy carriers. Cystic fibrosis fits this pattern because it results from mutations in the CFTR gene and is typically expressed only when a person inherits two mutated copies. If both parents are carriers, there’s a 25% chance for each child to be affected, a 50% chance to be a carrier, and a 25% chance to be unaffected. This pattern is a classic example used to illustrate autosomal recessive inheritance. While Tay-Sachs disease and sickle cell disease are also autosomal recessive, Huntington disease is autosomal dominant, so it does not follow this pattern.