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Disease Profile

Hyperinsulinism due to glucokinase deficiency

Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.


US Estimated

Europe Estimated

Age of onset





Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.


Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.


dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.


recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.


Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.

Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.


Not applicable



Congenital and Genetic Diseases; Endocrine Diseases; Metabolic disorders


The following summary is from Orphanet, a European reference portal for information on rare diseases and orphan drugs.

Orpha Number: 79299

Hyperinsulism due to glucokinase deficiency (HIGCK) is a form of diazoxide-sensitive diffuse hyperinsulinism (see this term), caused by a lowered threshold for insulin release, characterized by an excessive/ uncontrolled insulin secretion (inappropriate for the level of glycemia) and recurrent episodes of profound hypoglycemia induced by fasting and protein rich meals, requiring rapid and intensive treatment to prevent neurological sequelae.

Prevalence for congenital isolated hyperinsulinism (CHI, see this term) is estimated at 1/50,000 live births. GCK alterations are noted in 1.2% of patients with non-syndromic CHI.

Clinical description
Clinical picture is similar to that described in CHI with mild manifestations leading to a delay in diagnosis until adulthood. A notable clinical feature is the remarkable stability of their hypoglycemia consistent with a resetting of the threshold for insulin release. The clinical spectrum can range from mild and intermediate cases that respond well to dietary modifications and medical management with diazoxide to severe cases that are unresponsive to diazoxide necessitating near-total pancreatectomy. The potential development of type 2 diabetes with age is another notable feature Neurological sequelae due to rapidly falling glucose levels are rare.

Activating mutations of GCK (7p15.3-p15.1) that encodes glucokinase have been identified to cause HIGCK. Glucokinase has been described as the glucose sensor of pancreatic betacells. These mutations localize to an allosteric activator site and increase the protein's affinity to glucose and its efficacy in ATP-dependent phosphorylation of glucose, causing resetting of the threshold for insulin release at a value lower than normal. Recently, a somatic activating mutation in GCK has been proposed as a cause of a novel form of diazoxide-responsive focal CHI. Inactivating mutations GCK have been identified in cases of maturity onset diabetes of the young 2 (MODY 2, see this term).

Genetic counseling
Most activating mutations of genes GCK identified to date are dominant. De novo mutations have also been reported.

Visit the Orphanet disease page for more resources.


This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Medical Terms Other Names
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80%-99% of people have these symptoms
Abnormal Cpeptide level
Fasting hyperinsulinemia
High blood insulin levels while fasting
Hyperinsulinemic hypoglycemia
Hypoketotic hypoglycemia
Recurrent hypoglycemia
Recurrent low blood sugar levels
30%-79% of people have these symptoms

[ more ]

Hand tremor
Tremor of hand
Tremor of hands
tremors in hands

[ more ]

Muscle weakness
Muscular weakness
5%-29% of people have these symptoms
Type II diabetes mellitus
Noninsulin-dependent diabetes
Type 2 diabetes
Type II diabetes

[ more ]

1%-4% of people have these symptoms
Abnormality of the autonomic nervous system

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These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

In-Depth Information

  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.