Alkaptonuria, also known as homogentisic acid oxidase (HGO) deficiency, is a rare genetic disorder that affects the body’s ability to break down the amino acid, homogentisic acid. It is an autosomal recessive disorder, meaning that both parents of an affected individual must carry the defective gene in order for the disorder to be passed on to their child. Symptoms of Alkaptonuria include dark urine, arthritis, and discoloration of the sclera of the eyes.
Diagnosis of Alkaptonuria is typically made through a combination of clinical testing and genetic testing. A doctor may first perform a physical examination to look for signs and symptoms of the disorder. Urine tests may also be done to check for the presence of homogentisic acid. Blood tests may be conducted to measure levels of homogentisic acid in the blood.
Genetic testing is the most definitive way to diagnose Alkaptonuria. Genetic testing involves looking for mutations in the HGO gene. Genetic tests can be done on a sample of blood, saliva, or cheek cells. It can also be done prenatally, through amniocentesis or chorionic villus sampling.
If Alkaptonuria is suspected, a doctor may also order imaging tests, such as an MRI or CT scan, to further evaluate the patient. These tests can help to identify any joint damage or discoloration of the connective tissue that is associated with the disorder.
In summary, Alkaptonuria is typically diagnosed through a combination of clinical testing, including urine and blood tests, as well as genetic testing. Imaging tests may also be used to confirm the diagnosis.