Which type of inheritance does Androgen Insensitivity Syndrome fall into?

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

Answer: (B)

Androgen Insensitivity Syndrome (AIS) is classified as X-linked recessive inheritance. This condition occurs due to mutations in the androgen receptor gene located on the X chromosome. In individuals with AIS, despite having XY chromosomes, the body cannot respond to androgens (male hormones), which results in the development of female physical traits or ambiguous genitalia.

Since the gene is located on the X chromosome, males, who possess only one X chromosome, are more likely to express the condition if they inherit a mutated allele. Females, with two X chromosomes, can be carriers if one of their X chromosomes has the mutation, but they typically do not express the full syndrome unless both of their X chromosomes carry the mutation, which is quite rare. This inheritance pattern illustrates how diseases linked to the X chromosome can show different expressions based on the sex of the individual carrying the allele.