Orotic aciduria

What is Orotic Aciduria?

Orotic aciduria, also known as orotic aciduria type I, is a rare inherited metabolic disorder in which the body is unable to break down the compound orotic acid. Orotic acid forms naturally in the body during the synthesis of certain nucleotides. When orotic acid levels become elevated, symptoms like metabolic acidosis, failure to thrive, and convulsions can occur. Affected individuals may also experience buildup of liver and kidney problems, weak muscles, and stunted overall growth.

Orotic aciduria is caused by mutations in the UMP synthase gene (UMPS), which is responsible for producing an enzyme needed to break down orotic acid. The condition is inherited in an autosomal recessive pattern, which means both copies of the UMPS gene in each cell have mutations. Most cases of orotic aciduria are caused by new mutations in the gene and occur in people with no history of the disorder in their family.

Signs and Symptoms of Orotic Aciduria

The main symptoms of orotic aciduria are related to metabolic acidosis, a disruption in pH balance in the body. Common symptoms can include:

  • Weak muscle tone
  • Irritability
  • Failure to gain weight
  • Lethargy
  • Fainting
  • Convulsions
  • Developmental delays

Diagnosis and Treatment of Orotic Aciduria

If the signs and symptoms of orotic aciduria are present, doctors will order laboratory tests to check for an elevation in orotic acid levels. Genetic testing is also used to confirm the diagnosis and identify the specific gene mutation causing the disorder. In some cases, a liver biopsy may also be recommended.

Treatment for orotic aciduria usually involves dietary management to reduce the levels of orotic acid in the body. This may include restricting certain foods or supplements, taking in additional protein, or supplementing with specific vitamins and minerals. In severe cases, medications may be prescribed to help reduce metabolic acidosis symptoms.

Outlook for orotic aciduria is dependent on the severity of the condition and how closely it is managed. With careful treatment, most affected individuals have a normal life expectancy. However, the disorder can cause damage to the liver and kidneys, so it is important to monitor and manage the condition closely.