A novel deletion mutation of ATP7A gene in a Chinese family with Menkes disease

Menkes disease is a rare X-linked recessive .hereditary disorder first described by Menkes et al in 1962.1 including The gene mutation results in clinical features pili torti, unusual facies, mental/growth retardation and metabolic dysfunction. The pathogenic gene ATP7A was identified in 1993.2 It is located on chromosome X and encodes a transmembrane Cu^2＋ transporter. Here we reported the clinical manifestations and results of genetic study of a family with Menkes disease. In this family, a deletion mutation in ATP7A gene is responsible for the disease.     

A novel mutation, Y255X, of the ARSB gene in a Chinese family with mucopolysaccharidosis type Ⅵ

Mucopolysaccharidoses (MPS) are lysosomal storage diseases with defectivedegradation of glycosaminoglycans. Mucopolysaccharidosis type Ⅳ( MPS Ⅳ )or Maroteaux-Lamy syndrome is caused by defective arylsulfatase B in the lysosomes ( ARSB; Nacetylgalactosamine-4-sulfatase, EC 3.1.6. 12 ) . The clinical manifestations of MPS VI include coarse facial features, growth retardation, short stature, skeletal malformations, hepatosplenomegaly, corneal clouding,and cervical myelopathy. Heart failure is the usual cause of death in the second or third decade of life. Despite all the physical disabilities, the intellect of MPS Ⅳ patients is preserved.     

A novel nonsense mutation in BBS4 gene identified in a Chinese family with Bardet-Biedl syndrome

Background Bardet-Biedl syndrome (BBS) is a genetically heterogeneous disease, and information about BBS in Chinese populations is very limited. The purpose of the present study was to determine the genetic cause of BBS in a Chinese Han family.

Methods Clinical data were recorded for the 4-year-old female proband and the available family members. The proband was screened for mutation by Sanger sequencing for a total of 142 exons of the 12 BBS-causing genes (BBS1-BBS12). The variants detected in the proband were further confirmed in the other family members.

Results We identified a novel homozygous nonsense mutation (c.70A>T, p.K24X) in the BBS4 gene exon 2 in the proband. Such mutant allele was predicted to cause a premature truncation in the N-terminal of the BBS4 protein, and probably induced the nonsense-mediated decay of BBS4 messenger RNAs. The proband’s parents and brother were heterozygous for the nonsense mutant allele. It was absent in 50 Chinese control subjects. An additional rare heterozygous missense single nucleotide polymorphism (SNP) named rs200718870 in BBS10 gene was also detected in the proband, her father and her brother. Some manifestations of the proband including atypical retinitis pigmentosa, choroidal sclerosis, high myopia, and early onset of obesity might be associated with this mutation in BBS4 gene. The proband’s father also reported surgical removal of an extra finger during childhood.

Conclusions The present study described a novel nonsense mutation in BBS4 gene in a Chinese family. This homozygous mutation was predicted to completely abolish the synthesis of the BBS4 protein. We also detected a rare heterozygous missense SNP in BBS10 gene in the family, but did not ?nd sufficient evidence to support the triallelic inheritance.

     

新的肾上腺脑白质营养不良基因突变1例的鉴定

目的：对1例肾上腺脑白质营养不良(ALD)患及其家系成员的ALD基因的突变类型进行鉴定。方法：以外周血RNA为模板，采用长链RT-PCR技术，分4个片段扩增ALD基因mRNA的编码序列，对4个PCR产物进行直接测序，筛查整个基因编码区,通过限制性内切酶酶切分析患及其家系成员基因组ALD基因片段，以进一步确证所发现的基因突变。结果：位于患ALD基因第6外显子的第508位密码子存在一个新的错义突变CCC→CTC(P508L)，患母亲为突变携带，患父亲和妹妹不存在此突变。结论：发现中国ALD患一个新的ALD基因突变，即P508L突变。     

Features of a Chinese family with cerebral cavernous malformation induced by a novel CCM1 gene mutation

Background Familial cerebral cavernous malformations （CCMs）, characterized by hemorrhagic stroke, recurrent headache and epilepsy, are congenital vascular anomalies of the central nervous system. Familial CCMs is an autosomal dominant inherited disorder and three CCM genes have been identified. We report a Chinese family with CCMs and intend to explore clinical, pathological, magnetic resonance imaging （MRI） features and pathogenic gene mutation of this family. Methods Totally 25 family members underwent brain MRI examination and clinical check. Two patients with surgical indications had surgical treatment and the specimens were subjected to histopathological and microstructural examination. In addition, polymerase chain reaction （PCR） and direct sequencing were performed with genomic DNA extracted from 25 family members＇ blood samples for mutation detection. Results Brain MRI identified abnormal results in seven family members. All of them had multiple intracranial lesions and four cases had skin cavernous hemangioma. T2-weighted sequence showed that the lesions were typically characterized by an area of mixed signal intensity. Gradient-echo （GRE） sequence was more sensitive to find micro- cavernous hemangiomas. There was a wide range in the clinical manifestations as well as the age of onset in the family. The youngest patient was an 8-year-old boy with least intracranial lesions. Histopathological and microstructural examination showed that CCMs were typically discrete multi-sublobes of berry-like lesions, with hemorrhage in various stages of illness evolution. They were formed by abnormally enlarged sinusoids and the thin basement membranes. A novel T deletion mutation in exon 14 of CCM1 gene was identified by mutation detection in the seven patients. But unaffected members and healthy controls did not carry this mutation. Conclusions The clinical manifestations were heterogenic within this family. We identified a novel mutation （c.1396delT） was the disease-causing mutation for this family and extended the mutational spectrum of CCMs.     

EDM1: a novel point mutation in cartilage oligomeric matrix protein gene in a Chinese family with multiple epiphyseal dysplasia

Background Multiple epiphysis dysplasia (MED) is a common skeletal dysplasia with a significant locus heterogeneity.In the majority of clinically defined.cases,mutations have been identified in the gen...     

A new mutation of PTCH gene in a Chinese family with nevoid basal cell carcinoma syndrome

Background Nevoid basal cell carcinoma syndrome （NBCCS） is a rare autosomal dominant disease characterized by a combination of development anomalies and a predisposition to tumour formation. Mutation of patched gene （PTCH）, considered the molecular defect of NBCCS, in a Chinese NBCCS family was investigated in this study.
Methods Genomic DNA was isolated from blood samples of all 12 members of this family. The mutated PTCH gene was screened by polymerase chain reaction amplification and direct sequencing. Results A new mutation of 3 bp （GAT deletion） was found in all seven affected members of this family. This mutation caused one aspartate deletion in the fourth transmembrane domain of the PTCH protein located within the sterol sensing domain （SSD）. This deletion was not found in any unaffected members of this family nor in 200 control samples.
Conclusions Our findings suggest that one 3-bp deletion in PTCH gene was the cause of nevoid basal cell carcinoma in a Chinese family through affecting the conformation and function of PTCH protein.     

A novel mis-sense mutation (G1381A) in the G6PD gene identified in a Chinese man

Objective　To detect new mutations among 29 glucose-6-phosphate dehydrogenase (G6PD) deficient individuals from Yunnan province. Methods　The nitroblue tetrazolium (NBT) method was used to screen G6PD deficient individuals. Mutation was identified by single strand conformation polymorphism (SSCP), amplification created restriction site (ACRS), amplification refractory mutation system (ARMS) and DNA sequencing. Results　Among 29 cases, 18 cases of G1388A, 1 case of C1004A, and 1 case of G1381A were identified. Nine cases remained to be defined. The G1381A mutation is a novel mis-sense mutation, with a substitution of threonine for alanine (A461T). The resultant G6PD had reduced enzymatic activity. In addition, G1381A caused a restriction site of Stu I to disappear, providing a rapid method for the detection of this mutation. Conclusion　A novel mis-sense mutation G1381A was found. This mutation results in a substitution of threonine for alanine, producing enzyme with reduced activity. The loss of the Stu I restriction site offers a rapid method for the detection of this mutation.     

A novel CFTR mutation found in a Chinese patient with cystic fibrosis

Background Cystic fibrosis (CF) is rare in Chinese. We investigated the mutations in the gene of cystic fibrosis transmembrane conductance regulator ( CFTR ) in a Chinese CF patient and reviewed the clinical features, gene mutations in Chinese CF cases. Methods Blood samples were collected from a previously reported CF girl and her parents. The 24 coding exons of CFTR of the proband were amplified and sequenced. Results A Chinese girl of 16 years old was diagnosed as CF at the age of 14. She had recurrent productive cough with bronchiectasis in bilateral upper lobes, parasinusitis and otitis media, but without pancreatic involvement. Her sweat chloride was (108.9 ±3.3) mmol/L. A heterozygous novel missense mutation of 699 C → A which results in the amino acid change of N189K was identified in exon 5. In addition, a heterozygous 3821-3823 delT mutation in exon 19 was found in CFTR . The mutation 699C → A was inherited from her father, and the 3821-3823delT mutation was from her mother. Twenty patients with CF in Chinese reported from 1974 to 2004 were also reviewed. DelF508 mutation was not found in the nine cases whose CFTR mutations were analyzed. Conclusions The CF proband carries two heterozygous mutations (699C → A and 3821-3823delT) in CFTR . 699C → A mutation is a novel mutation which is not reported previously. Review of reported Chinese cases suggests that the genotype of Chinese CF may be different from those of white cases. More studies are needed to understand the spectra of CFTR and clinical CF features in Chinese.     

家族性慢性良性天疱疮一家系致病基因新突变的发现

目的对家族性慢性良性天疱疮一家系的ATP2C1基因突变进行检测。方法采用聚合酶链反应扩增该家系患者和健康对照个体ATP2C1基因的全部外显子,直接测序法进行DNA测序,100例无亲缘关系的正常人作为对照。结果该家系患者ATP2C1基因内含子3的末端235-2碱基发生了1个腺嘌呤（A）→鸟嘌呤（G）的杂合性剪接位点突变。家系中健康对照个体及无亲缘关系的正常对照均未发现该突变。结论该剪接位点突变可影响基因转录和翻译产物,是ATP2C1基因新的特异性突变。     

A novel deletion-frameshift mutation in the S1 region of HERG gene in a Chinese family with long QT syndrome

Background The congenital Long QT syndrome (LQTS) is a hereditary cardiac channelopathy that is characterized by a prolonged QT interval,syncope,ventricular arrhythmias,and sudden death.The chromosome ...     

ABCD1基因新突变致肾上腺脑白质营养不良一家系的临床和病理特点分析

目的 总结ABCD1基因新突变导致肾上腺脑白质营养不良1例的临床、影像及病理特点.方法 详细收集该患者家系成员的临床资料;先证者行左侧顶叶立体定向脑组织病理检查;先证者及其父母、弟弟行ABCD1基因筛查.结果 先证者:①男性,11岁,少年起病,早期表现为进行性认知功能减退;本次卒中样发作起病,主要表现为突发喷射性呕吐伴低热,后出现言语含糊、右侧肢体偏瘫、头痛及视力下降.②血皮质醇降低,超长链脂肪酸增高.③头颅MRI示颞顶枕叶及胼胝体非对称性病灶,左侧为著.④左侧顶叶病变脑活检病理可见正常白质结构消失,髓鞘片状脱失,轴索大部分缺失及反应性星形细胞增生;小血管周围可见以T淋巴细胞浸润为主的淋巴套.⑤先证者ABCD1基因c.1493-1496del的核苷酸半合子变异,其母亲ABCD1基因c.1493-1496del的核苷酸杂合变异,其父亲和弟弟未发现ABCD1基因变异.结论 ABCD1基因c.1493-1496del新突变可导致肾上腺脑白质营养不良,该新发突变基因可能导致较独特的临床和影像学特征,病理特点表现为小血管周围淋巴套样炎细胞浸润及髓鞘片状脱失.     

一个遗传性耳聋伴前庭功能障碍家系的分子病因学研究

目的:对1个遗传性耳聋伴前庭功能障碍家系进行遗传方式?表型特征及致病基因的分析,以研究其分子病因?方法:对门诊1例遗传性聋伴眩晕患者进行家系调查?病史收集及相应的听力学和前庭功能检查?利用目标基因捕获和大规模平行测序技术,对家系先证者进行可能致病突变筛查,包括靶向104种与遗传性听力损失相关的基因和3个microRNA分子?进一步对获得的候选突变基因进行编码区序列验证分析?结果:目标基因捕获测序结果发现先证者COCH基因第11外显子上存在c.1458C>G(p.T352S)的杂合突变?进一步对家系中所有患者和有血缘关系的正常个体进行了遗传共分离分析,发现该杂合突变在该家系中仅有Ⅰ2?Ⅱ1?Ⅱ5?Ⅱ9?Ⅱ13和Ⅳ1存在相同的杂合突变,而Ⅱ11和Ⅲ1表现为该突变的纯合子,表明该杂合突变不存在共分离现象,因此可以排除其为该家系致病突变的可能性?对先证者Ⅲ14 COCH基因全部12个外显子的序列测定结果未发现其他突变?结论:此家系为常染色体显性遗传性非综合征型耳聋伴前庭功能障碍,但初步筛查结果未发现已知耳聋相关基因,包括COCH基因的可疑致病突变?因此,该家系的分子病因可能存在一新基因的突变?     

一个遗传性抗凝血酶缺陷症家系的表型与基因突变分析

目的：对一例遗传性抗凝血酶（AT）缺陷症患者及其家系成员进行凝血指标和基因表型分析,初步探讨其分子发病机制。方法：在Stago仪器上检测家系各成员外周血的血浆AT活性（AT:A）、AT抗原（AT:Ag）等凝血指标;提取外周血DNA并测序,定位基因突变位点;利用生物信息学软件分析突变对蛋白功能的影响。结果：先证者及其外祖母、父亲、母亲和弟弟的AT:A均有不同程度降低,且AT:Ag同步下降,所有家系成员蛋白S活性（PS:A）和蛋白C活性（PC:A）指标均无明显异常,表现为I型AT缺陷症。基因分析显示：先证者SERPINC1 基因存在第1号外显子c.1A＞G杂合错义突变（p.Tyr2stop）以及第5号外显子c.1005G＞A杂合同义突变;其父亲携带c.1A＞G杂合错义突变,其外婆、母亲和弟弟携带c.1005G＞A杂合同义突变。保守性分析显示,Tyr2在同源物种间高度保守;MutationTaster、PolyPhen-2和LRT三个在线生物信息学软件分析均显示p.Tyr2stop突变为“致病的、有害的”;蛋白模型分析显示,p.Tyr2stop突变会引起AT基因翻译过程提前终止,产生截短蛋白。结论：该先证者及家系成员AT:A和AT:Ag不同程度降低与SERPINC1 基因上存在的c.1A＞G杂合错义突变和c.1005G＞A杂合同义突变有关。     

A novel mitochondrial tRNA gene mutation in a chinese family with dilated cardiomyopathy and sensorineural deafness

Objective： To determine whether a mutation of mitochondrial DNA induces familial dilated cardiomyopathy in Chinese families with cardiomyopathy, and analyzed the correlation between the genotype and phenotype. Methods： Affected members in three Chinese families of the familial dilated cardiomyopathy underwent clinical evaluation and DNA analysis. Polymerase chain reaction and direct DNA sequencing were used to screen for mitochondrial DNA mutation. The type of mtDNA variations and clinical situation were analysed on the patients with mitochondrial DNA mutation. Results： The mitochondrial A3434G mutation was identified in one of the three families,the 3434 th nucleotide A was replaced by G, which led to change of amino acid. No mutations were identified in the clinically unaffected members of the family and all members of the other two families. Conclusion： This study indicates that the mitochondrial A3434G mutation maybe related with familial dilated cardiomyopathy and deafness.     

先天性无虹膜家系致病基因的突变检测

目的 对一常染色体显性遗传的先天性无虹膜( AN)家系进行PAX 6基因突变筛查,以确定其致病基因及致病突变.方法 收集一常染色体显性遗传的AN家系,采集该家系患者、家族健康成员外周静脉血,提取基因组DNA,应用聚合酶链式反应( PCR)方法扩增PAX 6 基因exon 4 ~exon 13共11个外显子以及外显子-内含子拼接部,将纯化后的PCR扩增产物直接测序,运用DNAStar软件(综合性序列分析软件)对测序结果进行序列分析,检测PAX 6基因的突变类型,并与80名随机抽取的与该家系无血缘关系的健康人PAX 6基因序列进行比对. 结果 该家系患者PAX 6 基因exon 11存在一个杂合突变c. 949 C>T(P. R 317 X),导致第317位精氨酸的密码子CGA被终止密码子UGA替代,造成编码PAX 6蛋白的过早终止,而该家系其他健康成员及80名与该家系无血缘关系的健康对照组成员均未检测到该突变. 结论 PAX 6基因c. 949 C>T( P. R 317 X)突变导致PAX 6蛋白提前编码终止是该常染色体显性遗传先天性无虹膜家系的致病原因.     

Mutation analysis of PAX6 gene in a large Chinese family with aniridia

Background Mutations in PAX6 gene have been shown to be the genetic cause of aniridia, which is a severe panocular eye disease characterised by iris hypoplasia. However, there is no study to do genetic analysis of aniridia, although there are several case reports in China. Here, we describe a mutation analysis of PAX6 in a large Chinese family with aniridia.Methods Genomic DNA from venous blood samples was prepared. Haplotype analysis was performed with two genetic markers (D11S904 and D11S935 ). Fourteen exons of the PAX6 gene were amplified from genomic DNA. Polymerase chain reaction (PCR) products of each exon were analysed by single strand conformational polymorphism (SSCP). The PCR products having an abnormal pattern were sequenced to confirm the mutation.Results Significant evidence for allele sharing in affected patients was detected suggesting that PAX6 mutation links to aniridia in this family. An extra band corresponding to exon 9 in PAX6 was found by single strand conformational polymorphism analysis in all the aniridia patients in this family, but not detected in the unaffected members. A mutation of C to T was detected by sequencing at the nucleotide 1080 that converts the Arg codon (CGA) to the termination codon (TGA).Conclusions Aniridia is caused by a nonsense mutation of PAX6 gene in the large Chinese kindred. Genetic test is important to prevent the transmission of aniridia to their offsprings in the kindred by prenatal diagnosis.     

A SPG3A mutation with a novel foot phenotype of hereditary spastic paraplegia in a Chinese Han family

Hereditary spastic paraplegia （HSP） （MIM#182600） is a group of heterogeneous neurodegenerative disorders, with 35 underlying loci recognized by the HGNC （HUGO Gene Nomenclature Committee; http：//www.gene.ucl.ac.uk/nomenclature/） and 10 identified genes （ http ： //www. gene. ucl. ac. uk/cgi-bin/nomenc lature/ searchgenes.pl plus NIPA1, last search July 2006）. The mode of inheritance may be autosomal dominant, autosomal recessive or X-linked. Among these, autosomal dominant spastic paraplegia （AD-HSP） is the most common type, accounting for 70%-80% of all families. The disease is characterized by lower limb spasticity, hyperreflexia, progressive spastic gait and an extensor plantar response. Pes cavus is one of the commonly reported foot phenotypes.     

一先天性睑裂狭小-倒转型内眦赘皮-上睑下垂综合征家系FOXL2基因的突变检测

目的对一先天性睑裂狭小-倒转型内眦赘皮-上睑下垂综合征(BPES)家系进行FOXL2基因突变筛查,以确定其致病基因。方法抽取先天性BPES家系患者、患者家族成员及正常对照者外周静脉血,提取基因组DNA,PCR扩增,纯化后直接测序检测FOXL2基因的外显子及其与内含子交界处序列,DNAStar软件分析测序结果。结果在该家系患者中检测到C.578A>G错义突变,该突变导致193位氨基酸残基由赖氨酸突变为精氨酸。而家系中的正常人及100例正常对照者的FOXL2基因中均未发现突变。结论FOXL2基因C.578A>G错义突变使赖氨酸突变为精氨酸,导致蛋白质的改变,这可能是该家系BPES的致病原因。