Familial hyperglycemia due to mutations in glucokinase: definition of a subtype of diabetes mellitus

Mutations in the gene for glucokinase may be one of the causes of maturity-onset diabetes of the young, a type of adult-onset diabetes that occurs in young people. Glucokinase is an enzyme in the pancreas and liver that is involved in glucose metabolism. A study examined genetic mutations in glucokinase among individuals from 32 families with maturity-onset diabetes of the young and 21 families with adult-onset diabetes. DNA analysis revealed that over half the families with maturity-onset diabetes of the young had mutations in the glucokinase gene. Sixteen different mutations were found among individuals from 18 of these families No mutations in the gene for glucokinase were found among the individuals with late-onset diabetes. Patients with maturity-onset diabetes of the young whose families carried a gene defect usually began suffering from mild hyperglycemia in childhood, but those without these mutations were more likely to develop hyperglycemia after puberty.