BACKGROUND Mannosyl-oligosaccharide glucosidase(MOGS)deficiency is an extremely rare type of congenital disorder of glycosylation(CDG),with only 12 reported cases.Its clinical,genetic,and glycomic features are still e...BACKGROUND Mannosyl-oligosaccharide glucosidase(MOGS)deficiency is an extremely rare type of congenital disorder of glycosylation(CDG),with only 12 reported cases.Its clinical,genetic,and glycomic features are still expanding.Our aim is to update the novel clinical and glycosylation features of 2 previously reported patients with MOGS-CDG.CASE SUMMARY We collected comprehensive clinical information,and conducted the immunoglobulin G1 glycosylation assay using nano-electrospray ionization source quadruple time-of-flight mass spectrometry.Novel dysmorphic features included an enlarged tongue,forwardly rotated earlobes,a birth mark,overlapped toes,and abnormal fat distribution.Novel imaging findings included pericardial effusion,a deep interarytenoid groove,mild congenital subglottic stenosis,and laryngomalacia.Novel laboratory findings included peripheral leukocytosis with neutrophil predominance,elevated C-reactive protein and creatine kinase,dyslipidemia,coagulopathy,complement 3 and complement 4 deficiencies,decreased proportions of T lymphocytes and natural killer cells,and increased serum interleukin 6.Glycosylation studies showed a significant increase of hypermannosylated glycopeptides(Glc3Man7GlcNAc2/N2H10 and Man5GlcNAc2/N2H5)and hypersialylated glycopeptides.A compensatory glycosylation pathway leading to an increase in Man5GlcNAc2/N2H5 was indicated with the glycosylation profile.CONCLUSION We confirmed abnormal glycomics in 1 patient,expanding the clinical and glycomic spectrum of MOGS-CDG.We also postulated a compensatory glycosylation pathway,leading to a possible serum biomarker for future diagnosis.展开更多
目的探讨1例合并外耳发育不良的先天性糖基化障碍1y型(congenital disorder of glycosylation type 1y,CDG-1y)患儿的遗传学病因。方法采用家系全外显子测序法(trio-whole exome sequencing,trio-WES)检测相关基因的变异,通过Sanger测...目的探讨1例合并外耳发育不良的先天性糖基化障碍1y型(congenital disorder of glycosylation type 1y,CDG-1y)患儿的遗传学病因。方法采用家系全外显子测序法(trio-whole exome sequencing,trio-WES)检测相关基因的变异,通过Sanger测序法对候选变异进行验证,并对其致病性进行生物信息学预测。结果患者为男性,10岁,主要表现为智力障碍、小头畸形合并先天性外耳发育不良。trio-WES检测发现患儿携带X染色体SSR4基因第4外显子c.302dupC(p.Y102Lfs*2)半合子移码变异,既往未见报道。Sanger测序在患儿父母中均未发现同样的变异,故属于新发变异(de novo)(PS2);在主要人群基因频率数据库中均未收录(PM2)。多种软件预测结果均提示其为致病变异(PP3)。UCSF chimera软件分析提示,该变异可使SSR4蛋白空间结构严重变形,导致生物学功能的丧失(PVS1+PM1)。根据ACMG指南,判断为致病性变异(PVS1+PS2+PM1+PM2+PP3)。结论SSR4基因c.302dupC(p.Y102Lfs*2)可能为患儿罹患CDG-1y的原因。上述发现拓宽了SSR4基因的变异谱以及CDG-1y的表型谱。展开更多
基金Supported by National Science and Technology Major Project,No.2014ZX09101046-004(to Chen L)National Natural Science Foundation of China,Nos.81873543 and 81570468(to Wang JS).
文摘BACKGROUND Mannosyl-oligosaccharide glucosidase(MOGS)deficiency is an extremely rare type of congenital disorder of glycosylation(CDG),with only 12 reported cases.Its clinical,genetic,and glycomic features are still expanding.Our aim is to update the novel clinical and glycosylation features of 2 previously reported patients with MOGS-CDG.CASE SUMMARY We collected comprehensive clinical information,and conducted the immunoglobulin G1 glycosylation assay using nano-electrospray ionization source quadruple time-of-flight mass spectrometry.Novel dysmorphic features included an enlarged tongue,forwardly rotated earlobes,a birth mark,overlapped toes,and abnormal fat distribution.Novel imaging findings included pericardial effusion,a deep interarytenoid groove,mild congenital subglottic stenosis,and laryngomalacia.Novel laboratory findings included peripheral leukocytosis with neutrophil predominance,elevated C-reactive protein and creatine kinase,dyslipidemia,coagulopathy,complement 3 and complement 4 deficiencies,decreased proportions of T lymphocytes and natural killer cells,and increased serum interleukin 6.Glycosylation studies showed a significant increase of hypermannosylated glycopeptides(Glc3Man7GlcNAc2/N2H10 and Man5GlcNAc2/N2H5)and hypersialylated glycopeptides.A compensatory glycosylation pathway leading to an increase in Man5GlcNAc2/N2H5 was indicated with the glycosylation profile.CONCLUSION We confirmed abnormal glycomics in 1 patient,expanding the clinical and glycomic spectrum of MOGS-CDG.We also postulated a compensatory glycosylation pathway,leading to a possible serum biomarker for future diagnosis.
文摘目的探讨1例合并外耳发育不良的先天性糖基化障碍1y型(congenital disorder of glycosylation type 1y,CDG-1y)患儿的遗传学病因。方法采用家系全外显子测序法(trio-whole exome sequencing,trio-WES)检测相关基因的变异,通过Sanger测序法对候选变异进行验证,并对其致病性进行生物信息学预测。结果患者为男性,10岁,主要表现为智力障碍、小头畸形合并先天性外耳发育不良。trio-WES检测发现患儿携带X染色体SSR4基因第4外显子c.302dupC(p.Y102Lfs*2)半合子移码变异,既往未见报道。Sanger测序在患儿父母中均未发现同样的变异,故属于新发变异(de novo)(PS2);在主要人群基因频率数据库中均未收录(PM2)。多种软件预测结果均提示其为致病变异(PP3)。UCSF chimera软件分析提示,该变异可使SSR4蛋白空间结构严重变形,导致生物学功能的丧失(PVS1+PM1)。根据ACMG指南,判断为致病性变异(PVS1+PS2+PM1+PM2+PP3)。结论SSR4基因c.302dupC(p.Y102Lfs*2)可能为患儿罹患CDG-1y的原因。上述发现拓宽了SSR4基因的变异谱以及CDG-1y的表型谱。