中国10例戈谢病基因型与临床表型的相关性

The relationship between genotype and clinical phenotype in Chinese children with Gaucher's disease

目的 了解中国人戈谢病 (GD)基因型及其与临床表型的相关性。方法 10例中国GD患儿 (男 9,女 1。其中 5例Ⅰ型 ,2例Ⅱ型 ,3例Ⅲ型 ) ,来自无关的家庭 ,年龄 1 5～ 13岁。所有GD患儿的诊断是根据白细胞或成纤维细胞中 β 葡萄糖苷酶活性明显缺乏及骨髓象中出现戈谢细胞确定。采用巢氏聚合酶链反应扩增葡萄糖脑苷脂酶功能基因 ,产物覆盖了全部编码区 ;再分别扩增 11个外显子 ,用于限制酶切片断多态性 (RLFP) ,单链构像多态性 (SSCP)及序列分析。结果 5例Ⅰ型GD患儿的基因型是R48W R12 0W、G46E L44 4P、F37V L44 4P、N188S L44 4P及Y2 0 5C L44 4P ;2例Ⅱ型GD均为F2 13I L44 4P ;3例Ⅲ型GD为D40 9H D40 9H、G2 0 2R D40 9H及L44 4P L44 4P。检出了 2个新生突变F37V及Y2 0 5C。结论 中国GD患儿的L44 4P突变的等位基因频率最高 (40 % )。它同时出现在有神经病变及无神经病变的表型中。F2 13I、D40 9H及G2 0 2R突变基因型与有神经病变表型相关。

Objective Gaucher′s disease (GD) results from an inherited deficiency of the lysosomal enzyme glucocerebrosidase. Three clinical forms of GD have been described: type I, non neuronopathic; type Ⅱ, acute neuronopathic; and type Ⅲ, subactue neuronopathic. In this paper, the authors present the results of the mutation analysis for 10 Chinese GD patients and the relationship between genotype and phenotype. Methods All the 10 Chinese GD patients (9 male and 1 female, 5 had type Ⅰ, 2 type Ⅱ and 3 type Ⅲ) came from unrelated families, with the age ranged from 1.5～13 years. The diagnosis of GD in all the patients was confirmed by demonstration of profound deficiency of β glucosidase activity in WBC or cultured fibroblasts, and the presence of Gaucher′s cells in the bone marrow aspirates. A nested polymerase chain reaction (PCR) method was used to selectively amplify the glucocerebrosidase functional gene but not its pseudogene. Two pairs of functional gene specific primers were used in the first PCR to amplify exons 1 6 and 7 11. These regions cover the entire coding region. In the second PCR, each of the 11 exons was amplified and subjected to restriction fragment length polymorphism (RFLP), single stranded conformation polymophism (SSCP) and sequence analysis. Results The genotypes of 5 cases with type Ⅰ GD were R48W/R120W, G46E/L444P, F37V/L444P, N188S/L444P and Y205C/L444P; genotype of 2 cases with type Ⅱ GD was F213I/L444P; and genotypes of the 3 cases with type Ⅲ GD were D409H/D409H, G202R/D409H and L444P/L444P. Two novel mutations (F37V & Y205C) were detected. Conclusion This study showed that there was a high allele frequency (40%) of L444P mutation in Chinese GD patients. It was present in both nruronopathic and non neuronopathic phenotypes. The genotype of F213I, D409H and G202R mutation correlated with the neuronopathic phenotype.