An international team of researchers has identified the cause of a rare form of diabetes that affects newborn children. In a Brief Report in the May 24, 2001, issue of The New England Journal of Medicine, a team led by geneticists and physicians from the Universities of Chicago and Bergen, Norway; in collaborations with physicians from San Raffaele Scientific Institute, Italy, describe two cases of neonatal diabetes resulting from a complete deficiency of glucokinase, an enzyme that plays a crucial role in the regulation of blood-sugar levels.
Permanent neonatal diabetes mellitus is a rare disorder, occurring in about one in 400,000 live births. The two children described in the paper required insulin treatment beginning soon after birth.
"We believe this is the most common cause of permanent neonatal diabetes and urge physicians to look for glucokinase mutations in infants with diabetes, especially if the child has relatives with elevated blood sugar," said senior author Graeme Bell, Ph.D., professor of biochemistry & molecular biology, medicine, and human genetics and a member of the Howard Hughes Medical Institute at the University of Chicago.
In 1992, a team led by Bell discovered that glucokinase mutations were one cause of a sub-type of diabetes called maturity onset diabetes of the young (MODY). That defect appears to be relatively common and underdiagnosed.
"Finding glucokinase mutations that result in relatively mild disease as well as severe neonatal diabetes makes us suspect that there is a spectrum of glucose-regulation disorders that can be traced to different abnormalities of this gene," said Bell.
The parents of the Norwegian child were first cousins. The mother had type-1 diabetes and the father had elevated glucose levels, which he controls with diet. The patient's sister developed type-1 diabetes at age seven. The child, a girl, also had situs inversus, an unusual, probably genetic, condition in which the internal or
Contact: John Easton
University of Chicago Medical Center