GTP cyclohydrolase deficiency

GTP Cyclohydrolase I Deficiency is a rare genetic disorder that affects the body's ability to produce certain neurotransmitters, including dopamine and serotonin. This condition is caused by mutations in the GCH1 gene, which encodes the enzyme GTP cyclohydrolase I. This enzyme is crucial for the biosynthesis of tetrahydrobiopterin (BH4), a cofactor essential for the production of several important neurotransmitters. The deficiency can lead to a spectrum of clinical manifestations, ranging from mild to severe, and is involved in several distinct disorders, including Dopa-responsive dystonia (DRD) and Segawa syndrome.

Symptoms and Diagnosis

The symptoms of GTP Cyclohydrolase I Deficiency can vary widely among affected individuals but often include muscle stiffness, movement disorders, and developmental delays. In more severe cases, individuals may experience seizures, intellectual disability, and problems with autonomic nervous system regulation. The diagnosis of GTP Cyclohydrolase I Deficiency typically involves a combination of clinical evaluation, biochemical tests measuring neurotransmitter metabolites and BH4 levels in cerebrospinal fluid, and genetic testing to identify mutations in the GCH1 gene.

Treatment

Treatment for GTP Cyclohydrolase I Deficiency focuses on managing symptoms and may include supplementation with BH4, L-DOPA, and other medications aimed at restoring neurotransmitter balance. Early diagnosis and treatment are crucial for improving outcomes and preventing complications.

Genetics

The GCH1 gene, located on chromosome 14q22.1-q22.2, encodes the enzyme GTP cyclohydrolase I. Mutations in this gene lead to reduced activity of the enzyme, resulting in decreased production of BH4. The inheritance pattern of GTP Cyclohydrolase I Deficiency is typically autosomal dominant, but autosomal recessive inheritance has also been observed.

Epidemiology

GTP Cyclohydrolase I Deficiency is a rare condition, though the exact prevalence is unknown. Dopa-responsive dystonia, one of the disorders associated with GTP Cyclohydrolase I Deficiency, has an estimated prevalence of 1 in 2,000,000 individuals worldwide.

See Also

• Dopa-responsive dystonia
• Segawa syndrome
• Tetrahydrobiopterin deficiency
• Neurotransmitter
• Genetic disorder

GTP cyclohydrolase deficiency Resources
Latest articles Most recent articles Ongoing trials	Wikipedia