1. Hypomorphic homozygous mutations in phosphoglucomutase 3 (PGM3) impair immunity and increase serum IgE levels.
- Author
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Sassi A, Lazaroski S, Wu G, Haslam SM, Fliegauf M, Mellouli F, Patiroglu T, Unal E, Ozdemir MA, Jouhadi Z, Khadir K, Ben-Khemis L, Ben-Ali M, Ben-Mustapha I, Borchani L, Pfeifer D, Jakob T, Khemiri M, Asplund AC, Gustafsson MO, Lundin KE, Falk-Sörqvist E, Moens LN, Gungor HE, Engelhardt KR, Dziadzio M, Stauss H, Fleckenstein B, Meier R, Prayitno K, Maul-Pavicic A, Schaffer S, Rakhmanov M, Henneke P, Kraus H, Eibel H, Kölsch U, Nadifi S, Nilsson M, Bejaoui M, Schäffer AA, Smith CI, Dell A, Barbouche MR, and Grimbacher B
- Subjects
- Adult, Amino Acid Substitution, Cell Proliferation, Child, Chromosomes, Human, Pair 6 metabolism, Female, Genetic Diseases, Inborn enzymology, Genetic Diseases, Inborn immunology, Genetic Linkage, Glycosylation, Humans, Infant, Job Syndrome enzymology, Job Syndrome immunology, Male, Phosphoglucomutase immunology, Phosphoglucomutase metabolism, T-Lymphocytes enzymology, T-Lymphocytes immunology, Tunisia, Chromosomes, Human, Pair 6 genetics, Genetic Diseases, Inborn genetics, Homozygote, Immunity genetics, Immunoglobulin E, Job Syndrome genetics, Mutation, Missense, Phosphoglucomutase genetics
- Abstract
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., (Published by Mosby, Inc.)
- Published
- 2014
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