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.

Association between Polymorphisms of Insulin and Insulin Receptor Gene with Childhood Obesity in Malay Population / Jurnal Sains Kesihatan Malaysia

Childhood obesity is a global epidemic, which leads to the increasing number of studies on genetic locations associated with obesity-related traits. Polymorphisms of insulin (INS) gene have been shown to be associated with obesity-related phenotypes in Europeans; while insulin receptor (INSR) gene has been associated with energy regulation. Therefore, this study was conducted to investigate the association between the INS (rs689) and INSR (rs3745551) gene polymorphisms with childhood obesity risk in a Malay childhood population. Normal weight (538) and overweight or obese (557) children aged 6-12 years old were genotyped using semi-automated Sequenom iPLEX® Gold. Body mass index (BMI) was calculated from measured body weight and height. The rs689 (T/T: 0.006, A/T: 0.159 and A/A: 0.835) and rs3745551 (G/G: 0.054, A/G: 0.378 and A/A: 0.568) genotype distributions were consistent with Hardy Weinberg equilibrium. The T-minor allele frequency for rs689 was 8.6% and G-minor allele frequency for rs3745551 was 24.3%. Minor allele of INS gene polymorphisms significantly increased risk of obesity among Malay children (sex- and age-adjusted OR=1.580; 95%CI: 1.134-2.201). However, INSR gene polymorphisms were not significantly associated with childhood obesity. In conclusion, the polymorphisms of INS gene, rather than INSR gene, were associated with childhood obesity in the Malay population.

The effect of high-glucose-high-fat diet in male SD rats on methylation of INSR gene in F1 offspring / 中华内分泌代谢杂志

Objective To study the effect of high-glucose-high-fat diet on expression and methylation of insulin receptor ( INSR) gene in F1 offspring. Methods Sixty 5-week-old male SD rats were randomly divided into two groups:normal diet group and high-glucose-high-fat diet group. After rats were fed for three months, all male rats were performed to copulate with normal female rats. The body weight, blood glucose, and blood insulin of neonatal rats of F1 offspring were measured. The genome DNA, total RNA, and total protein were extracted from livers, brains, and muscles of neonatal rats. Relative expression of INSR in both mRNA level and protein level were detected using a realtime PCR test and a Western blot test respectively. Methylation of INSR promoter was analyzed by a methylation specific PCR ( MSP ) . Results Both body weight and fasting glucose were without significant difference in two groups. In high-glucose-high-fat diet group, both the glucose tolerance and insulin tolerance of neonatal rats in F1 offspring were significantly decreased. Except that in brains, the expressions of INSR gene in livers and in muscles of neonatal rats in high-glucose-high-fat diet group were down-regulated in mRNA ( realtime PCR ) and protein levels ( Western blot) compared to the normal diet group. Meanwhile, the methylation of INSR gene in livers and muscles were strengthened in high-glucose-high-fat diet group. Conclusion A high-glucose-high-fat diet fed to male SD rats leads to the decrease in glucose tolerance, insulin tolerance, and the inhibition of expression of hepatic and muscle INSR gene in neonatal offspring. The methylation of INSR gene could be involved in this phenomenon.

Insulin resistance syndromes of monogenic mutations / 中华内分泌代谢杂志

Several insulin resistance syndromes, such as severe insulin resistance syndrome caused by mutations of insulin receptor gene and lipodystrophy caused by mutations of lamin gene, have been characterized clinically. The gene mutations, pathogenesis and clinical features of these monogenie diseases were reviewed in this article.

Relationship between insulin-receptor gene polymorphism and ischemic cerebral vascular disease / 临床神经病学杂志

Objective To investigate the role of mutation of insulin receptor(IR) gene on the development of ischemic cerebral vascular disease.Methods The base variations at exon 17 and 20 of IR gene, by means of PCR SSCP were determined in the 68 cases of atherothrombotic cerebral infarction (ACI), 81 cases of lacunar infarction (LI) and 62 healthy controls.Results There were two alleles of T and C at exon 17 of IR gene. The prevalence of mutant of T allele in ACI patients was more common than that in the controls. The blood pressure and the parameters of blood sugar,lipid metabolism in the patients with mutant were higher than those in the controls with wild type gene. The correlative analysis showed the polymorphism of IR gene was not related statistically to the blood pressure. No base variation at exon 20 was found in the study.Conclusion By promoting the development of atherosclerosis,the mutation at exon 17 of IR gene may participate in the occurrence of ischemic stroke.