Alkaptonuria

Alkaptonuria is a rare disorder that occurs due to the buildup of homogentisic acid in the body. Resulting in urine or blackened body parts. Alkaptonuria is a genetic disorder inherited from parents. Symptoms of this disease are often overlooked and are seen after sufferers are aged 20-30 years. Homogentisic acid buildup occurs slowly causing cartilage, tendons, bones, nails or black colored ears.

Patients with alkaptonuria can live a normal life, even though the quality of life is disrupted due to joint pain or interference with the heart.

The symptoms.

• Symptoms of alkaptonuria can occur from infancy, marked by black spots on baby diapers.
• Symptoms become more apparent with age in the eyes, ears, nails, skin or other organs.
• Change the color of sweat.
• Nails turn blue.
• Skin color changes on the forehead, cheeks, armpits and genital area.
• Brown or gray stain on the whites of the eyes.
• Ear cartilage turns black and blue (ochronosis).
• Earwax turns black or reddish brown.
• Early symptoms of osteoarthritis, such as pain or stiffness in the joints and spine, shoulders, pelvis, knees.
• Shortness of breath or difficulty breathing.
• Blood vessels become stiff and weak.
• Heart valve disease.
• Formed kidney stones, prostate or bladder.

Cause.

Normal circumstances, the body will break down two protein-forming compounds (amino acids), namely tyrosine and phenylalanine through a series of chemical reactions. In the condition of alkaptonuria, the body cannot produce enough of the enzyme homogentisate oxidase. This enzyme is needed to break down the metabolism of tyrosine in the form of homogentic acid. As a result, homogentic acid accumulates and then becomes a black pigment in the body, some of it is excreted in urine.

• The inability of the body to produce the enzyme homogentisate oxidase is caused by a mutation in the gene producing the enzyme, namely genhomogentisate 1,2-dioxygenase (HGD).
• This disorder is inherited in an autosomal recessive manner, meaning that the gene mutation must be inherited from the two new parents causing this disorder, not just one.

Diagnosis.

• Urine examination to see homogentic acid content in urine.
• DNA testing to see if HGD gene mutations occur in the body.

Treatment.

• Slow the progression of the disease by adopting a diet low in protein to reduce levels of tyrosine and phenylalanine in the body.
• Provision of vitamin C to slow the buildup of homogentic acid in bones and cartilage.
• The administration of drug bernamanitisinone.
• Giving nitisinone to reduce levels of homogentic acid in the body. Nitisinone is an inhibitor of the enzymes that make up homogentic acid.

To prevent complications :

• Take pain relievers and inflammatory drugs to reduce joint pain.
• Physiotherapy with the help of a transcutaneous electrical nerve stimulation (TENS) tool to numb the spinal cord so that the pain subsides.
• Regular, moderate exercise to strengthen muscles and joints.