Sassi Atfa, Lazaroski Sandra, Wu Gang, Haslam Stuart M, Fliegauf Manfred, Mellouli Fethi, Patiroglu Turkan, Unal Ekrem, Ozdemir Mehmet Akif, Jouhadi Zineb, Khadir Khadija, Ben-Khemis Leila, Ben-Ali Meriem, Ben-Mustapha Imen, Borchani Lamia, Pfeifer Dietmar, Jakob Thilo, Khemiri Monia, Asplund A Charlotta, Gustafsson Manuela O, Lundin Karin E, Falk-Sörqvist Elin, Moens Lotte N, Gungor Hatice Eke, Engelhardt Karin R, Dziadzio Magdalena, Stauss Hans, Fleckenstein Bernhard, Meier Rebecca, Prayitno Khairunnadiya, Maul-Pavicic Andrea, Schaffer Sandra, Rakhmanov Mirzokhid, Henneke Philipp, Kraus Helene, Eibel Hermann, Kölsch Uwe, Nadifi Sellama, Nilsson Mats, Bejaoui Mohamed, Schäffer Alejandro A, Smith C I Edvard, Dell Anne, Barbouche Mohamed-Ridha, Grimbacher Bodo
Laboratory of Immunopathology, Vaccinology and Molecular Genetics, Pasteur Institute of Tunis and University Tunis El Manar, Tunis, Tunisia.
Center for Chronic Immunodeficiency (CCI), University Medical Center Freiburg, Freiburg, Germany.
J Allergy Clin Immunol. 2014 May;133(5):1410-9, 1419.e1-13. doi: 10.1016/j.jaci.2014.02.025. Epub 2014 Apr 1.
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.
We sought to elucidate the genetic cause in patients with HIES who do not carry mutations in STAT3 or DOCK8.
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.
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.
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.
复发性细菌和真菌感染、湿疹以及血清IgE水平升高是高IgE综合征（HIES）患者的特征。已知HIES的遗传病因是信号转导和转录激活因子3（STAT3）和胞质分裂 dedicator 8（DOCK8）的突变，它们参与信号转导途径。然而，HIES患者中尚未描述糖基化缺陷。糖基化途径中的一种关键酶是磷酸葡萄糖变位酶3（PGM3），它催化尿苷二磷酸N-乙酰葡糖胺合成中的关键步骤，而尿苷二磷酸N-乙酰葡糖胺是N-聚糖生物合成所必需的。
我们试图阐明在STAT3或DOCK8未发生突变的HIES患者中的遗传病因。
在来自突尼斯的2个HIES家族中通过SNP芯片基因分型和纯合性定位确定连锁区间后，采用基于选择器的高通量测序进行突变分析。通过蛋白质印迹分析蛋白质表达，并使用质谱分析糖基化情况。
对2个多重家庭共有的6号染色体上11.9 Mb连锁区域内候选基因的突变分析，在PGM3中鉴定出2个纯合突变，这些突变与疾病状态共分离并遵循隐性遗传。这些突变预测了PGM3中的氨基酸变化（p.Glu340del和p.Leu83Ser）。在另外2个受影响的家族中分别鉴定出第三个纯合突变（p.Asp502Tyr）和p.Leu83Ser变体。这些亚效突变对涉及尿苷二磷酸N-乙酰葡糖胺的生物合成反应有影响。糖组学分析显示白细胞中糖基化模式异常，三触角和四触角N-聚糖水平降低。患者的T细胞增殖和分化受损。大多数患者有发育迟缓，许多患者有精神运动发育迟缓。
PGM3功能受损导致一种新的原发性（先天性）发育和免疫缺陷，因为双等位基因亚效突变与糖基化受损和高IgE样表型相关。
