Related Experiment Videos
Insulin resistance in an infant with leprechaunism
Insights
This study investigated insulin resistance in a Japanese infant with leprechaunism. Findings suggest a defect in insulin receptors or post-receptor signaling, not insulin itself.
Area of Science:
- Endocrinology
- Metabolic Disorders
- Genetics
Background:
- Leprechaunism is a rare genetic disorder characterized by severe insulin resistance.
- Infants with leprechaunism often present with glucose intolerance and hyperinsulinemia.
Observation:
- A Japanese female infant with leprechaunism displayed significant glucose intolerance.
- Despite high circulating insulin levels (hyperinsulinemia), the infant showed signs of insulin resistance.
Findings:
- Insulin was chemically and biologically normal, with no antibodies detected.
- Erythrocyte insulin receptor assays revealed very low affinity and increased receptor numbers, suggesting a qualitative receptor abnormality or post-receptor defect.
Implications:
- This case highlights a potential qualitative defect in insulin receptors as a cause of severe insulin resistance in leprechaunism.
- Understanding these molecular defects is crucial for developing targeted therapies for metabolic disorders.
Abstract:
A Japanese female infant with typical features of leprechaunism exhibited glucose intolerance despite marked hyperinsulinemia, indicating insulin resistance. Circulating insulin appeared to be chemically and biologically normal. There was no evidence of antagonism of insulin action or circulating antibodies to insulin or insulin receptors. Insulin receptor assay of her erythrocytes showed very low affinity despite a six-fold increase in the number of receptors as compared with those of normal adult controls. Our studies indicate that insulin resistance in this patient appears to be due to a qualitative abnormality of insulin receptors or to a postreceptor defect.