Potassium channel, inwardly rectifying, subfamily J, member 11

The protein encoded by this gene is a potassium channel that regulates insulin secretion in pancreatic beta cells. Loss-of-funtion mutations cause autosomal recessive and less commonly dominant hyperinsulinemic hypoglycemia. Gain-of-function mutations, on the other hand, cause autosomal dominant permanent neonatal juvenile (MODY13) diabetes mellitus, a special case of which is DEND syndrome that is associated by neurological symptoms.

Protein Structure

The protein forms a heterodimer with SUR, the sulfonyl urea receptor.

Phenotype

Mutations inhibiting the beta cell result in permanent neonatal diabetes mellitus. On the other hand activating mutations lead to hyperinsulinemic hypoglycemia.

Pathology

The inwardly rectifying potassium conductance is activated by diazoxide and inhibited by sulfonyl urea, which results in decreased or increased insulin secretion. Mutations activating the channel and inhibiting its ATP inhibition result in reduced insulin secretion. The opposite is true for mutations that inhibit the channel conductance.

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	25 days
	Specimen type	genomic DNA

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