Hypomorphic homozygous mutations in phosphoglucomutase 3 (PGM3) impair immunity and increase serum IgE levels
2014 (English)In: Journal of Allergy and Clinical Immunology, ISSN 0091-6749, E-ISSN 1097-6825, Vol. 133, no 5, 1410-U681 p.Article in journal (Refereed) Published
Background: Recurrent bacterial and fungal infections, eczema, and increased serum IgE levels characterize patients with the hyper-IgE syndrome (HIES). Known genetic causes for HIES are mutations in signal transducer and activator of transcription 3 (STAT3) and dedicator of cytokinesis 8 (DOCK8), which are involved in signal transduction pathways. However, glycosylation defects have not been described in patients with HIES. One crucial enzyme in the glycosylation pathway is phosphoglucomutase 3 (PGM3), which catalyzes a key step in the synthesis of uridine diphosphate N-acetylglucosamine, which is required for the biosynthesis of N-glycans. Objective: We sought to elucidate the genetic cause in patients with HIES who do not carry mutations in STAT3 or DOCK8. Methods: After establishing a linkage interval by means of SNPchip genotyping and homozygosity mapping in 2 families with HIES from Tunisia, mutational analysis was performed with selector-based, high-throughput sequencing. Protein expression was analyzed by means of Western blotting, and glycosylation was profiled by using mass spectrometry. Results: Mutational analysis of candidate genes in an 11.9-Mb linkage region on chromosome 6 shared by 2 multiplex families identified 2 homozygous mutations in PGM3 that segregated with disease status and followed recessive inheritance. The mutations predict amino acid changes in PGM3 (p. Glu340del and p. Leu83Ser). A third homozygous mutation (p. Asp502Tyr) and the p. Leu83Ser variant were identified in 2 other affected families, respectively. These hypomorphic mutations have an effect on the biosynthetic reactions involving uridine diphosphate N-acetylglucosamine. Glycomic analysis revealed an aberrant glycosylation pattern in leukocytes demonstrated by a reduced level of tri-antennary and tetra-antennary N-glycans. T-cell proliferation and differentiation were impaired in patients. Most patients had developmental delay, and many had psychomotor retardation. Conclusion: Impairment of PGM3 function leads to a novel primary (inborn) error of development and immunity because biallelic hypomorphic mutations are associated with impaired glycosylation and a hyper-IgE-like phenotype.
Place, publisher, year, edition, pages
2014. Vol. 133, no 5, 1410-U681 p.
Hyper-IgE syndrome, glycosylation, Staphylococcus aureus, signal transducer and activator of transcription 3, dedicator of cytokinesis 8, phosphoglucomutase 3
Immunology in the medical area
IdentifiersURN: urn:nbn:se:uu:diva-227188DOI: 10.1016/j.jaci.2014.02.025ISI: 000335450700024OAI: oai:DiVA.org:uu-227188DiVA: diva2:729885