Identification of two novel mutations in Chinese patients with Dyschromatosis symmetrica hereditaria

Dyschromatosis symmetrica hereditaria (DSH) is a rare autosomal dominant cutaneous disorder characterized by a mixture of hyperpigmented and hypopigmented macules of various sizes on the extremities. Pathogenic mutations in the DSRAD gene have recently been identified. In this study, we report and identify the mutations of the DSRAD gene in two Chinese pedigrees with DSH. Two novel mutations in the functional domains of the DSRAD gene were identified and verified in two pedigrees. The c.3244A>G (H1075R) mutation was found in all patients but not in the healthy individuals from family A and c.3335_3336delAT (Y1112fs→1112X) mutation was found in three patients but not in the healthy family members from family B. Our data suggests that these two novel mutations in the DSRAD gene could cause DSH and add new variants to the repertoire of DSRAD mutations in DSH. Ming Li and Chengrang Li contributed equally to this work.     

A novel missense mutation in DSRAD in a family with dyschromatosis symmetrica hereditaria

Dyschromatosis symmetrica hereditaria (DSH) is a rare autosomal dominant cutaneous disorder characterized by a mixture of hyperpigmented and hypopigmented macules of various sizes on the extremities. Pathogenic mutations in the DSRAD gene have been identified. In this report, we identified a Chinese family with a three-generation pedigree of DSH, in which a novel heterozygous nucleotide G→A transition was found. It is at position 3,125 in exon 12 of the DSRAD gene which induces a R1042H change in the putative deaminase domain of DSRAD. Our study expands the database on the DSRAD gene mutations in DSH.     

Identification of a novel <Emphasis Type="Italic">ADAR</Emphasis> mutation in a Chinese family with dyschromatosis symmetrica hereditaria (DSH)

Dyschromatosis symmetrica hereditaria (DSH [MIM 127400]) is characterized by the presence of hyperpigmented and hypopigmented macules mostly on the dorsal aspects of the extremities. Genetic studies have identified mutations in the ADAR gene, encoding double-stranded RNA-specific adenosine deaminase, to be responsible for this disorder. Here, we found a novel deletion mutation in the ADAR gene, 2929delA, in a Chinese family with DSH. This mutation is located in codon 977 (AGC→GC), and leads to a frameshift and truncated protein of 250 amino acids with 76 novel amino acids prior to a premature stop codon. The truncated ADAR is predicted to lack the ADEAMc (tRNA-specific and double-stranded RNA adenosine deaminase) domain. This study should be useful for genetic counseling and prenatal diagnosis for affected families and in expanding the database on ADAR gene mutations in DSH. Quinghe Xing and Mingtai Wang contributed equally to this work.     

遗传性对称性色素异常症一家系DSRAD基因新突变

目的：检测遗传性对称性色素异常症家系中DSRAD基因的突变。方法：收集遗传性对称性色素异常症一家系成员的血样,PCR扩增DSRAD基因的全部外显子,并行DNA测序。以100例无家系背景,且无色素异常的成年人作对照。结果：该家系中的患者均存在DSRAD基因中第3463位碱基发生了C→T的杂合突变,可造成对应1155位的精氨酸被色氨酸替代,家系中非患病者及对照组正常人未发现相应突变。结论：DSRAD基因是遗传性对称性色素异常症的致病基因。     

遗传性对称性色素异常症一家系中不典型白癜风患者1例

目的：鉴定遗传性对称性色素异常症（DSH）一家系中1例不典型的白癜风患者是否发生DSRA D基因突变。方法：采集家系各成员的外周血,提取基因组DNA,利用基因组DNA的PCR扩增产物直接检测该白癜风患者DSRA D基因的突变情况。结果：该家系中所有DSH患者均携带CAA→TAA的无义突变,而该例不典型白癜风患者未发现DSRA D基因的突变。结论：基因检测结果排除该例发生不典型DSH的可能,结合该例的临床特点,最终诊断为白癜风。     

Identification of a novel mutation in the <Emphasis Type="Italic">DSRAD</Emphasis> gene in a Chinese pedigree with dyschromatosis symmetrica hereditaria

Dyschromatosis symmetrica hereditaria (DSH) is an autosomal dominant skin disorder characterized by a mixture of hyperpigmented and hypopigmented macules distributed on the face and dorsal aspects of the extremities that appear in infancy or early childhood. The DSH locus has recently been mapped to chromosome 1q21 and then pathogenic mutations have been identified in the DSRAD gene. In the study reported here we examined the DSRAD gene mutations of a three-generation Chinese pedigree with DSH by direct sequencing. We identified a novel heterozygous nucleotide TC transition at position 3388 in exon 14 of the DSRAD gene which induces a C1130R change in the putative deaminase domain of DSRAD. Our study expands the database on the DSRAD gene mutations in DSH and enriches the knowledge about the function of the DSRAD gene.     

Identification of two novel DSRAD mutations in two Chinese families with dyschromatosis symmetrica hereditaria

Dyschromatosis symmetrica hereditaria (DSH) is a hereditary skin disease characterized by the presence of hyperpigmented and hypopigmented macules on face and dorsal aspects of the extremities that appear in infancy or early childhood. Genetic studies have identified mutations in the double-stranded RNA-specific adenosine deaminase (DSRAD) gene, encoding double-stranded RNA-specific adenosine deaminase, to be responsible for this disorder. Here, we report two novel mutations c.2116 G > A (E706K) and c.2848 C > T (Q950X) in the DSRAD gene identified in two Chinese pedigrees with DSH. This study should be useful for genetic counseling and prenatal diagnosis for affected families and in expanding the database on DSRAD gene mutations in DSH.     

遗传性对称性色素异常症一家系致病基因的定位和突变研究

目的 探讨遗传性对称性色素异常症家系的致病基因。方法 明确先证者的临床诊断后,收集该家系成员的血样抽提基因组DNA,应用基因分型和连锁分析的方法进行基因定位,并对该定位区域内DSRAD基因直接测序,分析其突变位点。结果 基因分型和连锁分析将该家系的致病基因定位于1号染色体,和已知报道的区域一致。突变研究发现该家系所有患者的DSRAD基因2号外显子均携带CAA→TAA的突变,使得517位氨基酸由谷氨酰胺变成中止密码子。结论 该遗传性对称性色素异常症家系中的患者存在DSRAD基因的无义突变。     

遗传性对称性色素异常症一家系ADAR基因检测

目的：检测遗传性对称性色素异常症一家系的ADAR基因突变。方法：提取家系中患者、健康成员及无血缘健康对照人群外周血样DNA,PCR扩增ADAR基因外显子后测序。结果：该家系中患者均存在ADAR基因第2号外显子,第982位碱基突变（c.982C>T,p.R328X）,突变导致第328位的精氨酸被终止密码替代。家系中健康成员及健康对照人群未发现该突变。结论：该遗传性对称性色素异常症家系患者中的ADAR基因突变（c.982C>T,p.R328X）可能与发病有关。     

遗传性对称性色素异常症2个新的致病基因突变检测

目的检测遗传性对称性色素异常症2家系中DSRAD基因的突变。方法收集陕西籍遗传性对称性色素异常症2个家系成员资料,提取外周血DNA,PCR扩增DSRAD基因的全部外显子,进行DNA测序,并以50例无关正常人作为对照。结果家系Ⅰ所有患者中8号外显子检测到一新的c.2858C>G(p.S886R)错义突变;家系Ⅱ所有患者中10号外显子检测到一新的c.3073A>G(p.H958R)错义突变。结论DSRAD基因的c.2858C>G和c.3073A>G错义突变可能为引起这两个家系患者临床表型的病因。     

遗传性对称性色素异常症2例ADAR基因突变分析及家系调查

【摘要】 目的 对2个遗传性对称性色素异常症（DSH）家系进行家系调查并基因检测。方法 收集2家系DSH先证者及其家族成员的临床资料,同时采集先证者及其父母和100名无亲缘关系健康对照的外周血标本,应用二代皮肤靶向测序包检测基因突变,再用Sanger测序验证。结果 例1男,双手背、足背5岁时出现散在粟粒大小色素沉着斑和色素减退斑,母亲有类似表现。患者及母亲ADAR基因5号外显子检测到1个新的c.1970dupT（p.F657fs）杂合移码突变,父亲未检测到该突变。例2男,面颈部、腰背部、臀部、双下肢及双手足背夹杂分布米粒至黄豆大小褐色沉着斑和色素减退斑,父亲有类似表现,患者及父亲ADAR基因7号外显子检测到1个已知c.2433_2434delAG（p.T811fs）杂合移码突变,母亲未检测到该突变。无亲缘关系的100例健康对照均未发现上述突变。结论 本研究在DSH患者中检测到1个新的ADAR突变位点c.1970dupT。     

遗传性对称性色素异常症两家系DSRAD基因突变分析

目的对2例遗传性对称性色素异常症(DSH)家系DSRAD基因中可能存在的突变进行鉴定。方法收集的两个遗传性对称性色素异常症家系和100份无亲缘关系正常人外周血标本,采用聚合酶链反应(PCR)方法扩增DSRAD基因的全部外显子并测序,结果和Genbank中相应序列进行比对。结果家系1中所有患者DSRAD基因检测到第9外显子存在一个旧的错义突变c.G2747A,导致p.R916Q;在家系2所有患者第12外显子发现一个新的错义突变c.C3124T,导致p.R1042C。两家系中正常人及无亲缘关系对照均未发现突变。结论两家系中均存在DSRAD基因的变异,导致编码蛋白的结构和功能发生改变。     

一个遗传性对称性色素异常症家系ADAR1基因突变分析

目的 检测1个遗传性对称性色素异常症家系中ADAR1基因的突变位点。方法 提取一遗传性对称性色素异常症家系成员（5例患者,3例非患者）和100例无血缘关系的健康对照外周血标本,PCR扩增ADAR1基因全部15个外显子序列并测序,参考Genebank中ADAR1基因标准序列对比分析突变位点。结果 该家系5例患者ADAR1基因2号外显子第1 420位碱基C突变为T,为无义突变,即C.1420C > T（p.Arg474X）,家系其他健康成员和100例无关健康人中未发现此突变。结论 该遗传性对称性色素异常症家系的致病突变为ADAR1基因C.1420C > T无义突变。     

遗传性对称性色素异常症一家系基因检测

目的 探讨遗传性对称性色素异常症(DSH)家系中双链RNA特异性腺苷脱氨酶(DSRAD)基因的突变.方法 收集患者临床资料,提取外周血DNA,PCR扩增DSRAD基因的全部外显子,并行DNA测序,以100例正常人作对照.结果 检测到家系中患者均存在DSRAD基因中第3076位碱基发生C→T的杂合突变,即c.3076C>T,对应1026位的精氨酸被色氨酸替代(p.R1026W),家系中未患病者及对照组正常人未发现相应突变.结论 发现p.R1026W错义突变是遗传性对称性色素异常症的致病基因的一个新突变,扩大DSH致病基因的突变谱.     

遗传性对称性色素异常症2例基因诊断

目的:鉴定1例遗传性对称性色素异常症(dyschromatosis symmetrica hereditaria,DSH)患者ADAR1(adenosine deaminase acting on RNA1)基因突变,并对该家系中一临床不典型病例进行基因诊断.方法:采集1例DSH患者及家族成员的外周血,应用直接测序的方法检测突变位点.结果:在患者10号内含子区域检测到1个剪接位点突变(c.2886-5T>C).另外,对该家系中临床表现不典型的患者,基因测序结果支持该病的诊断.结论:该研究检测到1例新的剪接位点突变,异常剪接方式为外显子的删除.并明确了该家系中临床不典型患者的诊断,在Wood灯下进一步确定了其临床表型.     

两个遗传性对称性色素异常症家系的DSRAD基因剪切突变

目的研究两个遗传性对称性色素异常症(DSH)家系中的DSRAD基因突变情况。方法收集了2个遗传性对称性色素异常症家系的外周血标本,用聚合酶链反应(PCR)扩增DSRAD基因的全部外显子并测序,检测2个家系中的患者及正常人和100例无关正常人的DSRAD基因。结果家系1中所有患者的DSRAD基因第6号内含子与第7号外显子交界处检测到一新的c.2271-3AG剪切突变。家系2中所有患者的DSRAD基因第12号外显子与第12号内含子交界处检测到一新的c.3202+5GA剪切突变。2家系中的正常人及100例无关正常人未发现突变。结论 2个DSH家系患者均有DSRAD基因剪切部位突变,可能由此引起非正常的基因剪切,导致编码蛋白的结构和功能改变,致皮肤色素异常。