A novel heterozygous missense mutation of Trp1220Gly in the insulin receptor gene associates with type A insulin resistance syndrome: A case report / 中华内分泌代谢杂志

We report a case of type A insulin resistance syndrome. A 16-year-old girl with BMI of 19.1 kg/m 2 presented with primary amenorrhea and hyperglycemia for two years. Baseline HbA 1C was 10.8%, along with severe hyperinsulinemia, increased total testosterone and free androgen index(FAI). Ultrasonography showed polycystic ovaries. Next generation sequencing identified a novel and de novo heterozygous missense mutation of Trp1220Gly in the insulin receptor gene. Short-term intensive insulin pump treatment was initiated, followed by insulin glargine, pioglitazone and acarbose combination regiment. Fasting blood glucose and insulin levels decreased significantly, but post-load hyperglycemia and hyperinsulinemia remained unsatisfactory. HbA 1C dropped to 7.6% at 1-year follow up. Patients with polycystic ovarian syndrome who are adolescent-onset and with lean body type should be taken into account of type A insulin resistance syndrome. Currently, there is no standardized treatment protocol, and therapy should be individualized based on the specific gene mutation of each patient.

The changes of insulin secretion in type A insulin resistance syndrome: a 7-year follow up / 中华内科杂志

Objective A previously reported female diagnosed with type A insulin resistance syndrome bearing a heterozygous missense mutation of R1174W in the insulin receptor gene was followed for 7 years since the age of 16 years. Methods Five-hour oral glucose tolerance tests (OGTT) were done on baseline, the 3rd, 6th and 7th year respectively, with serum insulin and C-peptide measured at the same time points. Areas under of curve (AUC) of glucose, insulin and C-peptide were compared between the years.Acute insulin response (AIR) was determined at baseline and the 7th year. The dose response were insulin secretion rates at each time point during OGTT being plotted over the corresponding glucose levels, and the slopes of which quantified the insulin secretion responding to glucose. Results The follow up data showed that the glucose metabolism of the subject did not deteriorate over time with yearly glycosylated hemoglobin A1c (HbAlc) being normal (4.6%-5.5%), and hyperinsulinemic hypoglycemia was a persistent phenomenon observed at 4-5 hours post-load. The fasting and AUCs of serum insulin and C-peptide tended to decline without simultaneously increase of those of plasma glucose. The AIR decreased by 56% as compared to baseline. The dose response curves shifted downward as years went by. Conclusions It supports that with the alleviation of physiological insulin resistance after puberty, the gross hyperinsulinemia tends to ameliorate, and β-cell secretion does not deteriorate over time as glucose homeostasis maintains.