Every Dark Urine is not Hematuria - A Novel Mutation Associated with Alkaptonuria.

A 3-year-old boy came to our outpatient department with complaints of dark urine noticed by the mother since birth. On examination, the child had dysmorphic facies, synophrys, hypertelorism, micrognathia, prominent lashes, and difficulty in vision. The weight and height were below the third centile. Urinalysis showed glucosuria; tandem mass spectrometry and gas chromatography-mass spectrometry showed high levels of homogentisic acid and glycerol-3-phosphate. Exome sequencing revealed a missense homozygous variant in the gene encoding homogentisate 1,2-dioxygenase. A diagnosis of alkaptonuria was made and the patient was started on a low-protein diet and ascorbic acid. [ABSTRACT FROM AUTHOR]