Hartnupkór

Hartnupkór is a rare, inherited metabolic disorder that affects the body's ability to absorb certain amino acids. It is caused by mutations in the SLC6A19 gene, which is responsible for producing a transporter protein in the kidneys and intestines. This protein is crucial for reabsorbing essential amino acids, particularly neutral amino acids like tryptophan, from the urine and digestive tract back into the bloodstream. When this transporter is faulty, these amino acids are lost in the urine, leading to a deficiency in the body.

The symptoms of Hartnupkór can vary widely, even among individuals in the same family. Some people with Hartnupkór have no noticeable symptoms, while others experience a range of issues. The most common manifestation is pellagra-like skin rashes, especially in areas exposed to sunlight. Neurological symptoms can also occur, including difficulty with coordination (ataxia), tremors, headaches, and sometimes intellectual disability or psychiatric problems. These neurological symptoms are thought to be related to the deficiency of tryptophan, which is a precursor to serotonin, a neurotransmitter.

Diagnosis of Hartnupkór is typically made through urine and blood tests that measure amino acid levels. Genetic testing can confirm the diagnosis by identifying mutations in the SLC6A19 gene. There is no cure for Hartnupkór, but it can be managed effectively. Treatment primarily involves dietary supplementation with niacin (vitamin B3) to prevent pellagra and potentially other amino acids to compensate for losses. Avoiding prolonged sun exposure is also recommended. With proper management, individuals with Hartnupkór can lead normal, healthy lives.