Homocystinuria due to defect in methylation (cbl g)

Homocystinuria due to defect in methylation (cblG) is a rare genetic disorder characterized by the body's inability to properly process certain building blocks of proteins (amino acids). Specifically, this condition affects the metabolism of the amino acid methionine, leading to an accumulation of homocysteine in the blood and urine, a condition known as homocystinuria. The cblG type is caused by mutations in the MMACHC gene, which plays a crucial role in the metabolic pathway that converts vitamin B12 (cobalamin) into its active forms. This defect disrupts the methylation cycle, essential for DNA synthesis and repair, as well as the production of myelin and neurotransmitters.

Symptoms

The symptoms of homocystinuria due to cblG defect can vary widely among affected individuals. They may include:

• Developmental delay
• Intellectual disability
• Seizures
• Microcephaly (small head size)
• Megaloblastic anemia (a type of anemia characterized by larger than normal red blood cells)
• Visual problems
• Skeletal abnormalities such as osteoporosis
• Thromboembolism (blood clots)

Diagnosis

Diagnosis of homocystinuria due to cblG defect involves a combination of clinical evaluation, family history, and specialized tests. These tests may include:

• Plasma amino acid analysis to measure levels of methionine and homocysteine
• Urine analysis for elevated homocysteine
• Genetic testing to identify mutations in the MMACHC gene

Treatment

There is no cure for homocystinuria due to cblG defect, but treatment focuses on managing symptoms and preventing complications. Treatment options may include:

• Vitamin B12 (cobalamin) supplements
• Betaine, a medication that helps reduce homocysteine levels
• A diet low in methionine
• Regular monitoring for complications such as blood clots and eye problems

Prognosis

The prognosis for individuals with homocystinuria due to cblG defect varies depending on the severity of the condition and the effectiveness of treatment. Early diagnosis and treatment can improve the quality of life and reduce the risk of serious complications.

Homocystinuria due to defect in methylation (cbl g) Resources
Latest articles Most recent articles Ongoing trials	Wikipedia