Hypoglycemia in CDG patients due to PMM2 mutations: Follow up on hyperinsulinemic patients.

Abstract

BACKGROUND:

Phosphomannomutase 2 deficiency (PMM2-CDG) is the most common congenital disorder of glycosylation (CDG). Hypoglycemia has been reported in various CDG including PMM2-CDG. The frequency and etiology of hypoglycemia in PMM2-CDG are not well studied.

METHODS:

We conducted a systematic review of the literature on genetically and/or biochemically confirmed PMM2-CDG patients who developed hypoglycemia. Prospective follow-up information on the patients who received diazoxide therapy was collected and evaluated.

RESULTS:

A total of 165 peer-reviewed articles reporting on 933 PMM2-CDG patients were assessed. Hypoglycemia was specifically mentioned only in 23 of these patients (2.5%). Hyperinsulinism was identified in 10 patients (43% of all hypoglycemic patients). Among these 10 patients, seven were successfully treated with diazoxide. However, most patients remained on therapy longer than a year to stay free of hypoglycemia.

CONCLUSION:

Hypoglycemia is a rarely reported finding in patients with PMM2-CDG. Diazoxide-responsive hyperinsulinism was found to have a good prognosis on medication in our PMM2-CDG patients with hypoglycemia. No genotype-phenotype correlation was observed with respect to hyperinsulinism. A prospective study should be undertaken to explore the hypothesis that hypoglycemia is underdiagnosed in PMM2-CDG and to evaluate whether hyperinsulinism is always associated with hypoglycemia.

• Authors: Hossein Moravej, Ruqaiah Altassan, Jaak Jaeken, Gregory M Enns, Carolyn Ellaway, Shanti Balasubramaniam, Pascale De Lonlay, David Coman, Saadet Mercimek-Andrews, Peter Witters, Eva Morava
• Journal: JIMD reports (JIMD Rep) Vol. 51 Issue 1 Pg. 76-81 (Jan 2020) ISSN: 2192-8304 [Print] United States
• PMID: 32071842 (Publication Type: Journal Article)
• Copyright: © 2019 The Authors. Journal of Inherited Metabolic Disease published by John Wiley & Sons Ltd on behalf of SSIEM.