Recent Advances in the Care of Patients with Juvenile Diabetes Mellitus
Norman P. Spack MD1
1 The Department of Pediatrics, Children's Hospital Medical Center, Boston
GENETICS AND ETIOLOGY: IMPLICATIONS FOR COUNSELING
Until recently, diabetics were classified into juvenile- or maturity-onset categories on the basis of the age at onset of disease. We now consider diabetes to be a syndrome in which various factors, diminished or absent beta cell secretory capacity, increased levels of gluconeogenic hormones, or altered insulin receptor binding, can produce the common denominator of hyperglycemia.
Although a rare form of mild diabetes has been characterized in children and appears to be inherited in autosomal dominant fashion (termed MODY-Maturity Onset Diabetes of the Young)1, the overwhelming majority of diabetic children and adolescents develop the insulin-dependent variety of the disease. Recent studies in Michigan define the prevalence of the latter form to be 1.89 cases per 1000 school-aged children (ages 5 to 18 years), with an annual incidence of 1.6 cases per 100,000 children (ages 5 to 18 years). Whereas increased risk has long been observed in relatives of insulin-dependent diabetics, several factors have confounded the geneticists: patients sharing the same genetic blueprint do not share equal likelihood for developing the disease. When one member of a monozygotic twinship develops diabetes under age 45, his twin has but a 50% chance of becoming diabetic. On the other hand, if a twin develops the disease over the age of 45, the risk to the other twin approaches 100%.
