Congenital disorder of glycosylation type IIc

A rare genetic disorder affecting glycosylation

Classification
External resources

Overview

Congenital disorder of glycosylation type IIc (CDG-IIc), also known as Leukocyte adhesion deficiency type II (LAD II), is a rare genetic disorder that affects the process of glycosylation, which is the attachment of sugars to proteins and lipids. This disorder is characterized by defects in the synthesis of glycoproteins and glycolipids, leading to a wide range of clinical manifestations.

Pathophysiology

Glycosylation is a critical post-translational modification process that occurs in the endoplasmic reticulum and Golgi apparatus of cells. In CDG-IIc, there is a defect in the transport of fucose, a type of sugar, into the Golgi apparatus. This defect is due to mutations in the SLC35C1 gene, which encodes a GDP-fucose transporter. As a result, fucosylation of glycoproteins and glycolipids is impaired, affecting their function.

Clinical Features

Patients with CDG-IIc typically present with a variety of symptoms, including:

• Recurrent bacterial infections due to impaired leukocyte adhesion and migration.
• Developmental delay and intellectual disability.
• Distinctive facial features such as a depressed nasal bridge and a broad nasal tip.
• Growth retardation and short stature.
• Hypotonia and joint abnormalities.

Diagnosis

The diagnosis of CDG-IIc is based on clinical evaluation, laboratory tests, and genetic testing. Laboratory findings may include:

• Elevated levels of leukocytes with impaired adhesion properties.
• Abnormal glycosylation patterns on serum glycoproteins.
• Genetic testing revealing mutations in the SLC35C1 gene.

Management

There is currently no cure for CDG-IIc, and treatment is primarily supportive. Management strategies may include:

• Antibiotic prophylaxis to prevent infections.
• Physical therapy to improve motor skills and muscle tone.
• Nutritional support to address growth issues.
• Multidisciplinary care involving specialists in genetics, immunology, and neurology.

Prognosis

The prognosis for individuals with CDG-IIc varies depending on the severity of the symptoms and the effectiveness of supportive care. Early diagnosis and intervention can improve the quality of life for affected individuals.

Related pages

• Congenital disorder of glycosylation
• Leukocyte adhesion deficiency
• Glycosylation
• Genetic disorder