Evidence Hub

Rabson-Mendenhall syndrome caused by a novel splice-site mutation (c.1123+2 T>C) of insulin receptor: A case report and review of literature

Wang K, Zheng J, Gu LC, Li RR, Su XD, Bai J, Liao L

World journal of diabetes, 2026

Abstract

Background: Rabson-Mendenhall syndrome (RMS) is an extremely rare monogenic form of diabetes caused by mutations in the insulin receptor (INSR) gene, with only about 50 cases reported worldwide to date. Here, we report a case of RMS caused by a previously unreported c.1123+2 T>C splice mutation.

Case summary: The patient was diagnosed with acanthosis nigricans and hypertrichosis at birth, and the growth rate was slower than that of normal children. At age 5, the patient had severe hyperinsulinemia, congenital heart abnormalities, and pineal cysts. At age 13, he was diagnosed with diabetes and exhibited symptoms of hyperinsulinemia, low body weight, growth retardation, acanthosis nigricans, dental anomalies, an oversized penis, and a pineal cyst. Sequencing results indicated an INSR c.1123+2 T>C mutation, and bioinformatic analysis suggested that this mutation led to splicing abnormalities, thereby affecting INSR function. Both parents carried the mutated gene, whereas his brother had a normal genotype.

Conclusion: Genetic diagnosis is vital in RMS; c.1123+2 T>C mutation of INSR causes pancreatic decline; current treatments show limited effectiveness.

How strong is the evidence?

Evidence Hub reads this as a case report, done in people. Its evidence level is 5 of 5 (Very low · case / narrative / animal / in vitro / in silico). Case reports, narrative reviews, and animal, cell or computer-model studies give the weakest evidence for human health.

How the five levels of evidence work. The level is assigned automatically from the abstract and can be wrong, so check the paper.

Read the paper

Related studies

Go deeper in Evidence Hub

Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.

Open this study Sign up free