Glucokinase

Glucokinase is a key enzyme in regulation insulin secretion. Heterozygous inactivating mutations in GCK cause maturity-onset diabetes of the young type 2 (MODY2), whereas activating mutations result in hypoglycemia.

Epidemiology

MODY 2 diabetes is one of the most common types of MODY. About 10% of MODY in Germany is caused by glucokinase mutations. Mutations of glucokinase could be found wordlwide.

Gene Structure

The gen is located on chromosom 7 (7p15-p13). Its abbreviation is GCK. Size is about 45kb. It consists of 12 exons, 10 of them are translated.

Phenotype

Clinically mutation of this gene impresses as autosomal dominant MODY 2 Diabetes. Biochemically the picture is similar to type 2 diabetes but manifestation is early in life and there is no metabolic syndrome. The diabetes becomes apperent in situations of metabolic stress ie. in pregnancy or during medication with glucocorticoids.

Pathology

Glucokinase is an important enzyme in glucose metabolism. It is involved in degradation of glucose and produktion of ATP. Tis way the enzyme is regulates insulin secretion.

Test Strategy

Patients with family history and laboratory data suspect for MODY diabetes. Screening of family member in a known MODY family.

Interpretation

The detection of a mutation in this gene is a prerequisite for the diagnosis.

Genetests:

Clinic	Method	Carrier testing
	Turnaround	5 days
	Specimen type	genomic DNA

Clinic	Method	Massive parallel sequencing
	Turnaround	25 days
	Specimen type	genomic DNA

Clinic	Method	Genomic sequencing of the entire coding region
	Turnaround	20 days
	Specimen type	genomic DNA

Clinic	Method	Multiplex Ligation-Dependent Probe Amplification
	Turnaround	20 days
	Specimen type	genomic DNA

Related Diseases:

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