How to treat the little-known alkaptonuria?

Medically speaking, alkaptonuria is an autosomal recessive genetic disease, which is called alkaptonuria. This means that most people who suffer from this disease have problems with their chromosomes, and the disease will be passed on to the next generation, so this disease is often difficult to prevent. Today, I will give you a detailed introduction to the treatment and causes of alkaptonuria.

Treatment measures

For children diagnosed at an early stage, dietary therapy can be tried, reducing protein intake, or only reducing phenylalanine and tyrosine intake, but nutritional needs must be guaranteed. According to reports, large amounts of vitamin C have certain benefits, but there is no cure for late-stage ocher disease.

Etiology

This disease is caused by congenital deficiency of homogentisate oxidase, so the homogentisate produced by the decomposition of tyrosine cannot be further decomposed into acetoacetate. Excessive homogentisate is excreted in the urine and oxidized to black in the air.

Clinical manifestations

A large amount of homogentisic acid can be excreted in the urine during the neonatal period. The color of fresh urine is normal, but it turns brown or black when left in the air. The amount of acid excreted in urine is related to the intake of phenylalanine and tyrosine. The child has no other discomfort. Ochromatosis may occur in adulthood, which is due to the long-term deposition of oxidized homogentisic acid in connective tissue, causing the median, sclera, nose, cheeks, etc. to turn brown or blue-black. In the late stage, it may be accompanied by osteoarthritis.

Diagnosis

In this disease, there is a large amount of homogentisic acid in the urine, but the homogentisic acid level in the blood is not high. The urine turns black when exposed to the air, and the color becomes darker when alkaline substances are added; when the urine is strongly acidic, it is not easy to turn black. The urine of the child reacts with ferric chloride to form a dark purple reaction; the urine reduction substance test (Banner's test solution) is dark brown; the urine turns black when saturated silver nitrate insoluble solution (dissolved with ammonia) is added. The above screening method can be confirmed by chromatography, spectrophotometry, or homogentisic acid oxidase activity measurement. It is not difficult to distinguish it from other substances that can turn urine dark (such as bilirubin, porphyrin, myoglobin, hemoglobin, etc.).