Homogentisic Acid Urine

The Homogentisic Acid (HGA) Urine Test measures HGA levels in urine to diagnose alkaptonuria, a rare metabolic disorder that affects the breakdown of tyrosine and phenylalanine.

This test is recommended for:

• Infants with suspected metabolic disorders.
• Individuals experiencing dark-colored urine, arthritis, or ochronosis (bluish-black pigmentation of connective tissues).
• Those with a family history of alkaptonuria.

A random urine sample is collected and analyzed using gas chromatography-mass spectrometry (GC-MS) or high-performance liquid chromatography (HPLC) to detect homogentisic acid.

• High HGA levels: Confirms alkaptonuria, resulting from defective homogentisate 1,2-dioxygenase (HGD) enzyme activity.
• Normal HGA levels: Rules out alkaptonuria but does not eliminate the possibility of other metabolic conditions.

Early detection of alkaptonuria enables timely management, preventing complications such as ochronosis and degenerative arthritis.