MPI-CDG

MPI-CDG (Mannose Phosphate Isomerase Congenital Disorder of Glycosylation)

Structure of Mannose

MPI-CDG, also known as Mannose Phosphate Isomerase Congenital Disorder of Glycosylation, is a rare genetic disorder that affects the process of glycosylation, which is the attachment of sugars to proteins and lipids. This disorder is part of a larger group of conditions known as Congenital Disorders of Glycosylation (CDG).

Pathophysiology

MPI-CDG is caused by mutations in the MPI gene, which encodes the enzyme mannose phosphate isomerase. This enzyme is crucial for the conversion of mannose-6-phosphate to fructose-6-phosphate, a key step in the glycolysis and glycosylation pathways. The deficiency of mannose phosphate isomerase leads to an accumulation of mannose-6-phosphate and a shortage of mannose-1-phosphate, disrupting normal glycosylation processes.

Clinical Features

Patients with MPI-CDG typically present with a range of symptoms, which may include:

• Failure to thrive
• Hepatomegaly
• Hypoglycemia
• Coagulopathy
• Gastrointestinal issues

The severity of symptoms can vary widely among affected individuals.

Diagnosis

Diagnosis of MPI-CDG involves a combination of clinical evaluation, biochemical testing, and genetic analysis. Biochemical tests may reveal abnormal glycosylation patterns, while genetic testing can confirm mutations in the MPI gene.

Treatment

Treatment for MPI-CDG is primarily supportive and symptomatic. Dietary supplementation with mannose has been shown to improve symptoms in some patients, as it can bypass the metabolic block caused by the enzyme deficiency.

Prognosis

The prognosis for individuals with MPI-CDG varies depending on the severity of the condition and the response to treatment. Early diagnosis and management can improve outcomes and quality of life.

Related pages

• Congenital Disorders of Glycosylation
• Glycosylation
• Genetic disorders