Question

Alkaptonuria is caused due to

• A. Dominant autosomal gene
• B. Recessive autosomal gene
• C. X-linked recessive gene
• D. X-linked dominant gene

Answer 1

The correct option is B Recessive autosomal gene

Alkaptonuria is caused due to recessive autosomal gene. It is one of the first metabolic disease described by Garrod in 1908. Mutations in the HGD gene can cause the rare disorder alkaptonuria. The gene usually produces an enzyme that breaks down a substance called homogentisic acid. When this enzyme doesn't function properly, the homogentisic acid builds up and causes symptoms of alkaptonuria that include arthritis, black urine and reddish earwax. The most commonly affected tissues are cartilages, joints, ligaments, tendons.

Therefore, the correct answer is option B.