Question

Alkaptonuria is a disease where the urine is
A. Yellow
B. White
C. Orange
D. Black

Answer 1

Hint: Alkaptonuria is an inherited genetic disorder of phenylalanine and tyrosine metabolism. Ochronosis is the buildup of dark pigments in connective tissues such as cartilage and skin. It is also characteristic of disorders. Diagnosis is affirmed by quantitative analysis of HGA in urine.

Complete Answer:
Alkaptonuria is also known as black urine. Black urine disease is an inborn mistake of amino acid metabolism. It is an autosomal recessive condition.

Causes of alkaptonuria:
- Mutation or defect in HGD gene, which causes lack of the enzyme homogentisate dioxygenase.
- This causes a buildup of homogentisic acid (HGA) in the bones, cartilage and urine.
- Homogentisic acid is an intermediate in the degradation’s pathway of the amino acids (phe and tyr) to the krebs cycle.

Symptoms:
- Urine becomes black when exposed to atmospheric air.
- Black spots on the sclera of the eye.
- Discolored ear and dark earwax.
- Kidney, prostate and bladder stones due to buildup of HGA in the genitourinary tract, while urine production.

Thus, the option (D) is correct.

Note: This condition is rare, it is affecting 1 in 250,000 to 1 million people around the world. This disease is common in Slovakia. Treatment for this disease is high dose of vitamin C. this has been shown to decrease the build- up of brown pigments in the cartilage and may slow the development of arthritis.