What protein is alkaptonuria?

Alkaptonuria is a rare genetic disorder caused by a mutation in the HGD gene, which stands for homogentisate 1,2-dioxygenase. The HGD gene provides instructions for producing an enzyme called homogentisate 1,2-dioxygenase, which is involved in the breakdown of the amino acids phenylalanine and tyrosine. The mutated HGD gene leads to a deficiency or malfunctioning of the homogentisate 1,2-dioxygenase enzyme, resulting in the accumulation of a substance called homogentisic acid in the body. The excessive build-up of homogentisic acid leads to various symptoms and complications associated with alkaptonuria.