Definition

The MPI gene encodes phosphomannose isomerase, which converts fructose-6-phosphate to mannose-6-phosphate; this step plays a role in feeding the mannose pool required for N-glycosylation. Unlike PMM2-CDG, MPI-CDG does not show neurological involvement; it is characterized by protein-losing enteropathy, hepatic fibrosis, hypoglycemia, and coagulation disorders, and can be effectively treated with oral mannose supplementation.

Gene/region examined

MPI - Exon 1, MPI - Exon 2, MPI - Exon 3, MPI - Exon 4, MPI - Exon 5, MPI - Exon 6, MPI - Exon 7, MPI - Exon 8

Method

Sequence analysis

Accepted sample types

EDTA blood, AF, CVS

Inheritance

Inherited, autosomal recessive.

Related Tests

Inheritance Patterns

Describes how a genetic condition is passed on within a family. There are five main patterns

Go to term →

Carrier (Heterozygous / Homozygous)

Why it matters: In autosomal recessive inheritance, when each parent is a carrier (while both appear healthy), the chance of their child being born with the disease is 25% in each

Go to term →

VUS (Variant of Uncertain Significance)

This is the situation where the test has detected a change in the DNA, but the role of this change in the development of disease is unconfirmed.

Go to term →

How to Read a Genetic Test Result (Positive / Negative / VUS)

A genetic test result falls into three main categories

Go to term →

Types of Genetic Tests

A genetic test is a type of medical test that detects changes in genes, chromosomes or proteins. Today there are more than 77,000 genetic tests available.

Go to term →