黏多糖贮积症Ⅵ型表现型和基因型的相关性研究  

The correlation study of phenotype and genotype of mucopolysaccharidosis type Ⅵ

作　　者：姜煜[1] 郭源平 艾阳[1] 唐佳[1] 方子水 杜敏联[4] 郭奕斌[1] 

机构地区：[1]中山大学中山医学院医学遗传室,广东广州510080 [2]中山大学医学遗传室暑期科研小组,广东广州510080 [3]广东理工学院,广东肇庆526000 [4]中山大学附属第一医院儿科,广东广州510080

出　　处：《热带医学杂志》2017年第2期142-147,F0002,共7页Journal of Tropical Medicine

基　　金：国家自然科学基金(30772069);闽粤合作科研基金(71010025)

摘　　要：目的对3家拟诊为黏多糖贮积症Ⅵ型(MPSⅥ)的患儿及其父母进行芳香基硫酸酯酶B(ARSB)基因的突变检测,以阐明其分子发病机制并揭示MPSⅥ表现型和基因型的相关性。方法尿糖胺聚糖(GAG)定性检测后对患儿及其父母的DNA进行ARSB基因的PCR扩增及Sanger测序。对所发现的新突变,用变性高效液相色谱(DHPLC)法进行快速筛检,用多种生物信息学方法对新突变的致病性进行系列鉴定。结果家系1先证者为c.943C>T和c.1197C>G的复合杂合子;家系2先证者为c.523T>G/p.Y175D(新突变,父源)和c.1197C>G/p.F399L(母源)的复合杂合子;家系3先证者的E2和E3无扩增产物,而其父母均有400 bp和459 bp特异带。DHPLC结果显示,正常对照组和患儿母亲为正常单峰,而患儿及其父为异常双峰。正常和突变的ARSB蛋白的高级结构存在明显差异;突变点所在氨基酸在物种进化过程中具有高度保守性;Poly Phen-2和SIFT软件预测结果:Probably damaging(很可能有害)和Damaging(有害的)。结论家系2的p.Y175D是一新的致病性突变,为患儿发病的内在原因之一。家系1和2可确诊为MPSⅥ型,其表现型和基因型有显著的相关性;家系3虽经酶检确诊,临床症状、尿检结果也均与MPSⅥ型符合,但DNA水平未查到明确突变类型,其表现型与基因型的相关性有待进一步证实。Objective To clarify the pathogenesis of mucopolysaccharidosis type Ⅵ（MPS Ⅵ）and reveal the correlation between phenotype and genotype of MPS VI. Methods Urine GAG was qualitative determined. Arylsulphatase B（ARSB） amplicons were sequenced directly from genomic DNA of each participant,and detected for mutations. The DHPLC method was used to screen the new mutations,and the pathogenicity of the new mutants was identified by a series of bioinformatics methods. Results The proband of family 1 was a compound heterozygous of c.943C〉T and c.1197C〉G. The proband of family 2 was also a compound heterozygous,carrying the c.523T〉G/p.Y175D（a novel mutation from father）and c.1197C〉G/ p.F399L（from mother）. The amplification products of E2 and E3 of the proband of family3 failed to be obtained,but his parents had 400 bp and 459 bp specific bands. The screening results of DHPLC showed that normal control group and the mother of sick child had normal single peak,but the sick child and his father had the abnormal heterozygous double peaks. Compared with the normal ARSB zymoprotein,the advanced structure of mutant ARSB zymoprotein was obviously different. The results of cross species conservation analysis showed that the amino acid of the mutantion site was highly conserved in the evolution of species. The prediction results of Poly Phen-2 and SIFT software were probably damaging and damaging,respectively. Conclusions The p.Y175 D mutation in the family 2 was a novel pathogenic mutation,which was one of the internal causes of the disease. Family 1 and 2 were confirmed to diagnose asMPS VI,and its phenotype was significantly related to its genotype. Through the enzyme examination,and clinical symptoms and urine test results family 3 was confirmed as MPS VI,but failed in finding mutations at the DNA level,therefore,the relationship between the phenotype and genotype remained to be further confirmed.

关 键 词：黏多糖贮积症Ⅵ型 ARSB基因 新突变 鉴定 相关性 

分 类 号：R394.3[医药卫生—医学遗传学]