Which inheritance pattern is associated with Wiskott-Aldrich Syndrome?

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

Answer: (C)

Wiskott-Aldrich syndrome is caused by mutations in a gene on the X chromosome, so it follows an X-linked recessive inheritance pattern. This means affected individuals are usually male, while females are typically carriers. A mother who is a carrier has a 50% chance to pass the mutated gene to her sons (who will be affected) and to her daughters (who will be carriers). Fathers do not pass the condition to their sons, and there is no transmission from father to son in this pattern. Rarely, females can be affected if X-inactivation is skewed.