Mannose phosphate isomerase-congenital disorder of glycosylation leads to asymptomatic hypoglycemia

Abstract

Background: Mannose phosphate isomerase deficiency-congenital glycosylation disorders (MPI-CDG) is a rare autosomal recessive disorder caused by pathogenic variants in the MPI gene and characterized by digestive, hepatic, and endocrine-related symptoms. Herein, we reported a case of a 4-month-old baby with MPI-CDG confirmed by genetic testing. Case summary: Based on the age of the child and the present clinical symptoms (feeding difficulties, intractable diarrhea, vomiting, hepatosplenomegaly, recurrent hypoglycemia, coagulation disorder, and hypoproteinemia under the premise of anti-infection therapy), congenital glycosylation disorder was suspected, which was then confirmed by genetic testing. Her father carried a heterozygous deletion variant of exons 1–2 of the MPI gene, while her mother carried a heterozygous variant of C. 422C > T variant. It was suspected that a biallelic pathogenic variant of the MPI gene caused the CDG. Conclusion: MPI-CDG should be considered in infancy with unexplained hypoglycemia and recurrent digestive and endocrine system involvement. Also, if evident symptoms are present, a gene examination should be performed, as this could speed up the diagnosis assuring timely treatment.

Keywords

• Congenital disorders of glycosylation
• MPI gene
• Hypoglycemia
• Mild diarrhea