Alkaptonuria is considered by genetics, as an error that arises within the metabolism process, an unusual genetic alteration, where the urine of an individual adopts a dark brown pigmentation, when exposed to the air. This is why this unusual condition is included in the group of rare diseases, known as "natural errors of metabolism."
The first case of alkaptonuria in history was discovered in 1902 by Dr. Archibald Garrod, who in his research was able to find a gene that modifies the metabolic pathway. This disease was capable of generating arthritis in people that was accompanied by a flow of urine of a characteristic color (ocher yellow), coupled with this, alkaptonuria makes the bones and cartilage of people turn darker over time.
Alkaptonuria is considered the first disease to be assigned to a recessive hereditary failure. The causes of the appearance of this condition is due to the lack of an enzyme in the liver: the so-called "homogenism oxidase". The lack of this enzyme prevents the conversion of homogentisic acid, as a result of the metabolism of tyrosine and phenylalanine into acid maleylacetoacetate. The dark pigmentation of urine is due to the fact that once it comes into contact with air, the homogentisic acid that gathers in it, tends to suddenly oxidize.
This disease generally does not show symptoms, except for the fact that the color of the urine is almost black; However, in some children in lactation stage, if they can occur, especially if they have a family history of alkaptonuria. One of the consequences that arise as a result of this disease is the fact that the person passing a certain age (between 40 and 60 years) can begin to manifest arthritic pain.
Urinalysis is required in order to make a diagnosis. Regarding treatment, it has not yet been developed, which means that this condition cannot be treated. Although there are many specialists who consider that the intake of vitamin C, if taken in large quantities, can reduce the storage of the brown color in the cartilage, which in turn would allow the reduction of the growth of arthritis.
