congenital disorder of glycosylation type Ib

What is Congenital Disorder of Glycosylation Type Ib?

Congenital disorder of glycosylation type Ib (CDG-Ib) is an inherited metabolic disorder that impairs the production of glycoproteins, which are proteins that have attached carbohydrates. In type Ib, there is a defect in an enzyme called phosphomannose isomerase.

If left untreated, the disease can cause a wide array of problems including chronic diarrhea, a failure to grow at the expected rate, a loss of protein from the body, vomiting, low blood sugar, difficulty in forming blood clots, and liver disease.

CDG-Ib can be effectively treated by taking supplements of mannose, a sugar. With this supplement, life can be relatively normal. Without it, symptoms of the disease can be life-threatening. For this reason, early diagnosis and treatment is important.

CDG-Ib is distinct from other forms of CDG in that it does not affect the central nervous system. People with CDG-Ib are intellectually normal.

How common is Congenital Disorder of Glycosylation Type Ib?

CDG-Ib is extremely rare, although the exact frequency is unknown.

How is Congenital Disorder of Glycosylation Type Ib treated?

CDG-Ib is treated with oral supplements of mannose, a sugar. People with CDG-Ib who begin mannose treatment show improvement in most of the symptoms of the disease. Treatment with mannose must be lifelong.

What is the prognosis for a person with Congenital Disorder of Glycosylation Type Ib?

With early and regular treatment, a person with CDG-Ib can live a near-normal life. Without it, the disease can be fatal. Generally, the prognosis will vary depending on the severity of symptoms and their response to mannose treatment.