Alkaptonuria
Channel: JAM paeds
Date: 2021-01-04

Alkaptonuria (AKU), the first defined human genetic disease with a recessive trait, is caused by mutations within the homogentisate 1,2-dioxygenase (HGD) gene (3q13.33). This inborn error in the metabolism of phenylalanine and tyrosine is characterized by the inability to metabolize homogentisic acid (HGA). The raised HGA levels in plasma and extracellular fluid lead to ochronosis, the deposition of polymers of HGA as a pigment (ochronotic pigment) in the connective tissues including cartilage, heart valves, and sclera.[1,2] The distribution of this disease is equal in males and females because it is an autosomal recessive or autosomal dominant trait.