Clinical and gene mutation analysis of three children with late-onset glycogen storage disease type Ⅱ with hypertrophic cardiomyopathy
10.3760/cma.j.issn.0578-1310.2017.06.006
- VernacularTitle: 伴有肥厚性心肌病的晚发型糖原贮积症Ⅱ型三例临床和基因突变分析
- Author:
Jihang LUO
1
;
Wenjuan QIU
;
Di FANG
;
Jun YE
;
Lianshu HAN
;
Huiwen ZHANG
;
Yongguo YU
;
Lili LIANG
;
Xuefan GU
Author Information
1. Department of Pediatric Endocrinology and Genetics, Shanghai Institute of Pediatric Research, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
- Publication Type:Journal Article
- Keywords:
Glycogen storage disease typeⅡ (GSD Ⅱ);
Hypertrophic cardiomyopathy;
Acid α
-glucosidase (GAA);
Mutation
- From:
Chinese Journal of Pediatrics
2017;55(6):423-427
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the clinical and laboratory features of three children with late-onset type Ⅱ glycogen storage disease(GSD) who presented with hypertrophic cardiomyopathy and to analyze the effect of five mutations identified on the acid-α-glucosidase (GAA) activity and stability.
Method:Three cases of children with muscle weakness were included in this study.GAA activity was analyzed in Dried Blood Spot of the patients.DNA was extracted from peripheral blood in all the patients and their parents and subjected to polymerase chain reaction and directly sequencing of GAA gene.Five mutant pcDNA3.1-myc-his-GAA expression plasmids(p.G478R, p.P361L, p.P266S, p.Q323X, p.R672Q) were constructed and transient instantaneously transfected into 293T cells to analyze the enzyme activity and stability of GAA.
Result:All the three children had the onset of disease at 3 years or 1.5 years of age.They presented with developmental delay, muscle weakness and hypertrophic cardiomyopathy.GAA activity of 3 patients was 2.65, 3.55 and 1.51 pmol(punch·h)(8.00-98.02)respectively. Genetic analysis found 5 mutations (p.G478R, p. P361L, p. P266S, p. Q323X, p. R672Q), and all of these 3 cases had clinical manifestations and were diagnosed as late-onset type Ⅱ glycogen storage disease.Five mutant pcDNA3.1-myc-his-GAA expression plasmids were transfected into 293T cells.Five mutant enzyme activities were found to be only 9.9%-22.5% of the wild-type enzyme activity and the protein expression of the five mutants was 32.0%-63.9% compared with the wild type.
Conclusion:This study reports 3 children with late-onset GSD Ⅱ accompanied by hypertrophic cardiomyopathy and compensatory stage of cardiac function in addition to limb muscle weakness.Five pathogenic mutations were identified, and these 5 mutations result in decreased GAA activity and GAA expression by in vitro functional analysis.
