Two patients with type A insulin resistance syndrome carried mutation with insulin receptor gene c.3449T＞C

Objective To report two cases of type A insulin resistance syndrome with new insulin receptor gene mutations. Methods Clinical data, laboratory examination, imaging examination and mutation scanning of insulin receptor gene were collected, and type A insulin resistance syndrome reported by domestic and foreign scholars were analyzed retrospectively. Results One case had dry mouth, polydipsia and hyperandrogenemia, and another case had primary amenorrhea, both of them had insulin resistance. Two cases had heterozygous missense mutation in insulin receptor gene C.3449T＞c (p.L1150P). The mothers of the two probands all carried this mutation, while the fathers did not. This mutation has not been reported previously. Literature review shows that the onset age of this disease is young, and it is more common in women. BMI 20.37±5.47 kg/m2, fasting blood-glucose 4.50 mmol/L(4.10,13.00), the proportion of insulin resistance is 100%, 92.0% has acanthoid nigricans, and the proportion of Testosterone above normal is 81.3%, diabetes complications appear earlier. Conclusions Genetic analysis is helpfulfor the etiological diagnosis in children with severe insulin resistance.