两个肢带型肌营养不良2D型家系SGCA基因遗传分析和产前诊断

目的对中国汉族肢带型肌营养不良2D(limb-girdle muscular dystrophy type 2D,LGMD2D)型的2个家系进行SGCA基因分析,明确病因并在此基础上为该家系中的胎儿进行产前诊断,提供遗传咨询与指导。方法回顾性收集2017年6月至2018年1月在郑州大学第一附属医院就诊的2个LGMD2D型家系,提取先证者和其父母的外周血,通过探针杂交技术对先证者LGMD相关21个基因编码区及其侧翼序列进行高通量测序,进一步采用Sanger测序和/或荧光定量聚合酶链反应对先证者父母目标基因区域进行检测,同时验证变异来源;明确先证者病因后,进一步对家系中胎儿进行产前诊断。结果家系1:先证者存在SGCA基因c.218C>G(p.P73R)和c.101G>A(p.R34H)复合杂合变异;产前诊断结果显示,胎儿与先证者一样同时遗传了父母双方的致病变异,胎儿父母选择终止妊娠。家系2:先证者携带SGCA基因c.218C>T(p.P73L)和该基因第7和第8外显子杂合缺失复合杂合变异,但胎儿不携带上述两变异,家属选择继续妊娠。胎儿足月分娩,随访至2岁,肌酶谱、体格、运动和智力发育均未见异常。结论SGCA基因复合杂合突变是2个LGMD2D型家系的致病原因,其中c.218C>G(p.P73R)、c.218C>T(p.P73L)为尚未报道的新突变。基于高通量测序可快速、准确地对该病进行基因诊断和产前诊断。     

全外显子测序检测6个囊性肾病胎儿及其核心家系的致病突变

目的全外显子测序技术检测6个囊性肾病胎儿及其核心家系,寻找致病变异,为遗传咨询、产前诊断或植入前诊断提供遗传学数据支持。方法应用Illumina Hiseq2500测序平台,对超声检查提示为囊性肾病、染色体微阵列检测(CMA)未见异常的胎儿标本进行家系全外显子检测,参考数据库Human Genome 19(hg19/GRCh37),根据美国医学遗传学与基因组学学会指南(ACMG,2015)及指南应用建议评估变异致病性,对评级可疑致病位点应用Sanger测序验证。结果家系WES检出3个家系存在异常突变,其中1个家系的突变为遗传性,2个家系胎儿的突变为新发突变;余3个家系未检出明确致病突变。胎儿1 PKHD1基因c.5869G>A(父源)和c.9455delA复合杂合突变(母源),均为可能致病的变异。胎儿5 HNF1B基因c.826C>T杂合突变,为致病性新发突变。胎儿6 HNF1B基因c.1318G>T杂合突变,为可能致病性新发突变。Sanger测序验证结果与全外显子检测结果一致。结论对囊性肾病可运用家系核心成员全外显子检测,筛选出候选变异后进行Sanger测序验证,并对家系进行遗传分析,有助于遗传咨询、再次妊娠的产前诊断或辅助生殖的植入前诊断。本研究检出3个未见文献报道的可能致病突变位点,1个致病性突变位点已在个别文献报道但是未在国际公认数据库明确为致病突变位点,本研究拓宽了囊性肾病的致病基因位点谱。     

外显子捕获测序技术用于室间隔缺损胎儿遗传学病因检测

目的:探讨外显子捕获-高通量测序技术检测室间隔缺损(VSD)胎儿遗传学病因的可行性。方法:选择超声心动图诊断为VSD且微阵列比较基因组杂交(a CGH)和G显带检测结果均正常的19例胎儿作为研究对象;将已知的63个人类先心病致病基因作为检测靶点制作成捕获芯片,对各个样本DNA进行外显子捕获后高通量测序,数据经过滤、数据库比对、生物学软件分析得到最终病理性突变位点;病理性突变位点用Sanger测序验证。结果:19例VSD胎儿中共检测到1540个基因突变位点,数据库比对、生物信息学分析后得到8个病理性突变位点:JAG1 c.1078TG(p.C360G),CHD7 c.6718GT(p.D2240Y),NOTCH2c.6131GA(p.R2044H),MYH7 c.77CT(p.A26V),ZFPM2 c.2107AC(p.M703L),CHD7 c.7198CT(p.R2400W),HAND2 c.341GA(p.S114N),MLL2 c.12140_12168del GGCCGTTAGCAATAGGAACTACCCCTGAG(p.G4047Vfs*5),其中MYH7、ZFPM2两个突变点为已报道突变,其余6例未见报道。8个突变位点的Sanger测序结果与高通量测序结果一致。父母溯源分析均为新发突变。结论:外显子捕获芯片用于VSD胎儿遗传学检测可提高阳性检出率,具有较好的临床应用价值。     

21例产前超声高度怀疑先天性骨骼系统畸形胎儿的遗传学分析

目的探讨产前超声提示骨骼系统畸形胎儿的遗传学病因。方法回顾性纳入2019年1月至2020年8月就诊于河南省人民医院医学遗传研究所的产前超声高度怀疑胎儿骨骼系统畸形的孕妇21例(孕妇和配偶均无骨骼系统畸形),抽取羊水/脐带血、孕妇及其配偶外周血,行染色体核型分析、染色体微阵列分析或全外显子组测序,并对全外显子组测序检出的“致病性”“可疑致病性”“临床意义未明”变异行Sanger测序验证。采用描述性统计分析总结骨骼系统畸形胎儿的遗传学病因。结果染色体核型分析检出染色体异常5例(21-三体4例,18-三体1例)。染色体微阵列分析检出拷贝数变异异常1例(16p11.2微缺失综合征)。全外显子组测序检出单基因病10例,累及8个基因(SGMS2、FGFR3、DYNC2H1、WDR35、TBX5、COL2A1、FGFR2、ALPL);检出14个基因变异,包括7个数据库未报道过的新变异(DYNC2H1基因c.8129T>A、c.7126G>A、c.10307_10320del、c.2641G>T,WDR35基因c.3085G>A、c.491G>A,COL2A1基因c.1070G>T)。结论对于孕妇和配偶均无骨骼系统畸形但产前超声检查高度怀疑先天性骨骼系统畸形的胎儿,遗传因素是其先天性骨骼系统畸形的重要原因,主要包括染色体异常、拷贝数变异异常和单基因病。     

以转氨酶升高为主的多种酰基辅酶A脱氢酶缺乏症1例临床表现及基因分析

目的研究1例以转氨酶升高为主的多种酰基辅酶A脱氢酶缺乏症患者临床表现、实验室检查、肌肉活检及基因突变情况分析,并进行文献复习,为该病的早期诊断及治疗提供依据。方法收集1例7岁3月男性患儿的临床资料,采集患儿及父母血标本,采用二代基因测序检测致病基因,腓肠肌穿刺活检明确肌肉病变情况。结果患儿肌肉活检电镜结果示肌纤维内大量脂滴沉积。基因测序结果显示患儿的ETFDH基因存在c.1773_1774del AT p.(Cys592※)无义突变和c.389AT p.(Asp130Val)错义突变,考虑为复合杂合突变,患儿父母分别为携带者。结论临床上有转氨酶升高为主伴有心肌酶升高、运动障碍者,应尽早进行分子遗传学检查,有条件者行腓肠肌肌肉活检术,可以为患儿家庭提供准确的遗传咨询和产前诊断。     

新一代测序技术确诊1例遗传多囊肾病家系

目的明确1例肝肾发育异常患儿的遗传学病因。方法收集该患儿的家族史及临床资料,抽取患儿及其父母外周静脉血2 mL,对患儿基因组DNA进行新一代测序分析,并对疑似致病性突变位点进行Sanger测序验证及生物信息学预测。结果该患儿系第三胎第一产,前2胎均在围产期死亡,B超示多囊肾表现。该患儿为男性,4月大,腹部膨隆可触及质硬包块,腹部超声提示多囊肾并肝纤维化,新一代测序显示患儿PKHD1基因第30外显子c.3500TC(p.L1167P)杂合突变,遗传自母亲;另外患儿PKHD1基因第58外显子c.9235_9236del GCins AA(p.A3079K)杂合突变,来自父亲;父母表型均正常,这2个突变均为新发现的突变。结论该患儿是由PKHD1基因的复合杂合突变导致的常染色体隐性遗传多囊肾病(ARPKD),结合家族史推断,该家系前2胎可能同样患有ARPKD。新一代测序可对该类疾病明确诊断,并有助于遗传咨询,以避免该类悲剧的再次发生。     

PMM2基因新变异致先天性糖基化障碍1例临床及基因分析

本文报道1例PMM2基因新变异所致先天性糖基化障碍(PMM2-CDG)的临床特征及PMM2基因突变特点。患儿女,9个月,主要表现为精神运动发育落后伴肝酶异常,双耳稍大,内斜视(左),四肢肌张力稍高。Sanger测序结果显示患儿PMM2基因存在两处杂合变异点,分别为外显子5的c.430TC(p.F144L),外显子7的c.556GA(p.G186R),前者来自父亲,为已知热点致病变异,后者来自母亲,为未报道新变异。对于临床上不明原因的多脏器损害,特别是婴幼儿,合并全面性发育迟缓、神经系统疾病、肝功能损害、眼睛异常、外耳异常等,应考虑本病的可能,PMM2基因检测有助诊断,并可根据突变位点评估预后。     

三个X-连锁重症联合免疫缺陷病家系的IL2RG基因新突变及产前诊断

目的:对3个X-连锁重症联合免疫缺陷病(SCID)家系进行致病基因突变分析和产前诊断。方法:收集2017～2018年于深圳市妇幼保健院医学遗传中心就诊的3个X-SCID家系中先证者及家庭成员的外周血,提取DNA,应用高通量测序和Sanger测序筛查三个家系IL2RG基因的突变位点,并分析突变位点的致病性,继而对家系中的高危胎儿进行产前诊断。结果:共发现IL2RG基因3个致病突变,均未见报道。3个X-SCID家系分别发现IL2RG基因:c.272dupA(p.Tyr91*),c.245_246insC(p.P82Pfs*15)和c.507delG(p.Q169fs*170)突变。结论:IL2RG基因突变:c.272dupA(p.Tyr91*),c.245_246insC(p.P82Pfs*15)和c.507delG(p.Q169fs*170)分别是3个家系的发病原因。高通量测序结合Sanger测序对X-SCID的基因诊断具有重要的价值。     

两个Alstrom综合征家系 ALMS1基因变异分析及产前诊断

本研究报道了2个Alstrom综合征家系的遗传学病因, 并据此对再次妊娠的胎儿进行产前诊断。这2个家系先证者均存在不同程度视力异常, 现先证者母亲均再次妊娠, 就诊于郑州大学第一附属医院进行产前诊断。全外显子组测序及Sanger测序验证结果显示, 家系1的先证者为ALMS1基因c.6103C>T(p.Gln2035*)和c.6430C>T(p.Arg2144*)复合杂合变异, 父母分别为携带者;家系2的先证者为ALMS1基因c.9148₉149delCT(p.Cys3051Serfs*9)和c.12028delC(p.Leu4010Typfs*19)复合杂合变异, 父母分别为携带者;其中c.6103C>T(p.Gln2035*)、c.9148₉149delCT(p.Cys3051Serfs*9)和c.12028delC(p.Leu4010Typfs*19)均为新发现的变异位点。家系1胎儿携带c.6430C>T(p.Arg2144*)杂合变异, 遗传咨询后选择继续妊娠;家系2胎儿与先证者相同, 携带c.9148_...     

学龄期脑性瘫痪儿童髋关节发育与髋周肌肉状况的相关性分析

目的探讨学龄期脑性瘫痪(简称脑瘫)儿童髋关节发育与髋周肌肉状况的关系。方法 2015年4月至6月在广州康复实验学校进行康复训练的脑瘫患儿56例,其中痉挛型41例,不随意运动型9例,共济失调型4例,混合型2例;双瘫37例,四肢瘫16例,偏瘫3例。对全部患儿进行髋关节X线片检查,评定股骨头外移百分比(MP值),并且评定髋关节屈曲、内收、内旋肌肌张力、髋关节伸展、外展、外旋肌肌力。结果 56例脑瘫患儿中髋关节发育基本正常21例(37.50%),半脱位32例(57.140%),全脱位3例(5.36%)。Spearman相关分析显示,MP值与髋关节屈曲、内收、内旋肌肌张力呈正相关(P0.05),与髋关节伸展、外展、外旋肌肌力测试结果均呈负相关(P0.05)。结论学龄期脑瘫儿童髋关节发育与髋周肌肉状况相关。     

Prenatal diagnosis of fetal glutaric aciduria type 1 with rare compound heterozygous mutations in GCDH gene

Objective

Glutaric aciduria type 1 is a rare disease, with the estimated prevalence about 1 in 100,000 newborns. GCDH gene mutation can lead to glutaric acid and 3- OH glutaric acid accumulation, with clinical manifestation of neuronal damage, brain atrophy, microencephalic macrocephaly, decreased coordination of swallowing, poor muscle coordination, spasticity, and severe dystonic movement disorder.

DHCR7基因复合杂合变异致新生儿Smith-Lemli-Opitz综合征1例

本文报告了1例 DHCR7基因复合杂合变异导致的Smith-Lemli-Opitz综合征（Smith-Lemli-Opitz syndrome,SLOS）患儿。患儿生后即起病,以“多发畸形、喂养困难”为主诉从当地医院转诊至湖南师范大学第一附属医院（湖南省人民医院）。入院时体格检查见全身硬肿、头皮缺损、阴茎短...     

Decreased fetal movement prompts investigation of prenatal/neonatal nemaline myopathy: the possible merit of fetal movement count

We highlight the merit of fetal movement count to identify a fetus with neuromuscular disorder: nemaline myopathy. A 38-year-old 1-para woman not in a consanguineous marriage had decreased fetal movement. This, together with increased amniotic fluid volume, led us to perform detailed ultrasound examinations, which revealed stretch contracture of the knee joints, leading us to suspect fetal neuromuscular disorders. At 38(2/7), she gave birth vaginally to a 2444 g female infant. Her respiration was very weak, requiring respiratory support. Contractures of the upper/lower extremity joints and club feet were observed. All skeletal muscles were hypotonic. Biopsized muscle cells showed nemaline bodies, confirming the diagnosis of nemaline myopathy. Fetal movement count may contribute to the identification of fetal neuromuscular diseases, such as nemaline myopathy.     

汉族肥胖儿童黑皮质素4受体基因筛查

目的探讨肥胖儿童黑皮质素4受体(MC4R)的突变频率及其与临床生化指标改变的关系。 方法浙江大学医学院附属儿童医院等单位于2004—2005年，对200例肥胖及100例正常体重儿童，利用PCR及基因测序技术进行MC4R基因筛查，同时对200例肥胖儿童进行生化检测和口服葡萄糖耐量试验。 结果(1)200例肥胖儿童中检出杂合子错义突变、无义突变3例；100例对照组中未检出突变;Val103Ile基因多态性在两组中分别有6例、2例。肥胖组中发现了3个新的杂合子突变位点Val166Ile、Cys277Stop、Arg310Lys；肥胖组和对照组中同时检测到新的杂合子变异Leu23Arg。(2)MC4R突变组和非突变组的肥胖儿童BMI、ALT、AST、TG、CHO、WBISI比较均无统计学意义(P>0.05)。 结论(1)首次在汉族儿童人群中发现了MC4R基因3个新的杂合子突变位点(Val166Ile、Cys277Stop、Arg310Lys)。(2)Leu23Arg可能是汉族人群MC4R的基因多态性。     

Preimplantation genetic diagnosis for Niemann-Pick disease type B

BACKGROUND: Acid sphingomyelinase (ASM) deficient Niemann-Pick disease (NPD) is an autosomal recessive disorder caused by mutations in the ASM gene (SMPD1). More than 70 different mutations have been reported in this gene. NPD type B is the most common type in Saudi Arabia with a frequency of 1:40 000 to 1:100 000. The phenotype of Saudi Type B patients is more severe than patients reported from the West. Two mutations specific to Saudi patients have been inherited in the SMPD1 gene. Given the difficult management of the disease, we opted for a preventive approach to the suffering families by screening the whole SMPD1 gene for mutations followed by Preimplantation Genetic Diagnosis (PGD). METHODS: The family suffering from NPD-B underwent mutation screening for the entire SMPD1 gene followed by PGD using nested PCR and sequencing. RESULTS: A novel mutation in a family suffering from the same severe NPD-B phenotype is described in this report (W533R). After PGD, a singleton pregnancy ensued after transfer of one heterozygous and one normal embryo. Postnatal DNA testing of the newborn showed a normal homozygous genotype. CONCLUSIONS: This report reveals a new SMPD1 mutation responsible for similar Saudi severe phenotype, and the prevention of this disorder by PGD.     

Novel MYH8 mutations in 152 Han Chinese samples with ovarian endometriosis

Abstract

Endometriosis is a common gynecological disease affecting up to 10% of women at reproductive age. Prior combined studies implied that MYH8 mutations might exist in endometriosis. Here, 152 Han Chinese samples with ovarian endometriosis were analyzed for the presence of MYH8 mutations. Two heterozygous missense mutations in the MYH8 gene, c.1441A?>?C (p.I481L) and c.4057G?>?A (p.E1353K), were identified in our samples. These mutations were neither found in public databases nor detected in our 485 Han Chinese control women without endometriosis. The p.I481L-mutated sample belonged to 34-year-old, who had slightly elevated serum CA 125 (42.09?U/mL); while the sample with p.E1353K mutation belonged to 25 years old, who had a markedly increased serum CA125 (89.86?U/mL). The evolutionary conservation analysis results suggested that these MYH8 mutations caused highly conserved amino acid substitutions among vertebrate species. Both the mutations were predicted to be ‘disease causing’ by MutationTaster and SIFT programs. In addition, no association was observed between MYH8 mutations and the available clinical data. In summary, the present study identified two novel potential pathogenic mutations in the MYH8 gene in samples with ovarian endometriosis for the first time, implying that MYH8 mutations might play a positive role in the pathogenesis of endometriosis.     

A new compound heterozygous mutation in a female with 17α-hydroxylase/17,20-lyase deficiency,slipped capital femoral epiphysis,and adrenal myelolipoma

Abstract

17α-Hydroxylase/17,20-lyase deficiency (17-OHD) is a rare disease caused by mutations of the CYP17A1 gene. Slipped capital femoral epiphysis (SCFE) rarely occurs in adults. There are occasional reports of adrenal myelolipoma (AML) in 17-OHD. A 27-year-old Chinese female (46, XX) visited the hospital for SCFE and presented with continuous hypokalemia, absent spontaneous puberty, and hypertension. Hypergonadotropic hypogonadism was detected. The laboratory tests were consistent with 17-OHD. AML was considered based on the imaging examinations. A mutation analysis of the CYP17A1 gene identified the following compound heterozygous mutation: a frame-shift mutation, i.e. c.985_987delTACinsAA (p.Tyr329fs), that had been reported to be a common mutation in the Chinese population was found in exon 6. Another new nonsense mutation, i.e. c.1270C?>?T (p.Gln424*), that causes a premature termination codon was found in exon 8. Treatment with prednisone had poor efficacy. The administration of 0.75?mg dexamethasone and estradiol/dydrogesterone cyclic treatment significantly improved the patient’s symptoms. For the first time, we report a 17-OHD case accompanied by SCFE, AML, and a novel mutation site in the CYP17A1 gene. We provide insight into the clinical manifestations, genetic analysis, and treatment options of 17-OHD.     

A new compound heterozygous mutation in the CYP17A1 gene in a female with 17α-hydroxylase/17,20-lyase deficiency

Abstract

Background: Congenital adrenal hyperplasia due to 17α-hydroxylase/17,20-lyase deficiency (OMIM #202110) is a rare autosomal recessive disorder, which is caused by mutations of the CYP17A1 gene located on chromosome 10q24.3. It has been reported that the type of mutation of the CYP17A1 gene was associated with the extent of 17α-hydroxylase/17,20-lyase deficiency, and the prevalence of common mutation was different among ethnic groups.

Case: A 21-year-old Korean female presented with primary amenorrhea and sexual infantilism, and intermittent hypokalemic episodes. Laboratory test was consistent with hypergonadotropic hypogonadism. The karyotype was 46,XX[20]. Genomic DNA was extracted from peripheral blood leukocytes. All the eight exons of the CYP17A1 gene including flanking regions of introns were amplified by PCR. The mutations of the CYP17A1 gene were detected by direct sequencing. A compound heterozygous mutation was identified; one allele had a missense mutation of c.1118A>T (p.His373Leu), which was reported previously and induced the complete loss of both 17α-hydroxylase/17,20-lyase activity. This mutation has been known to be one of the common mutation types in East Asia. The other allele had a novel 1-bp deletion c.1148delA causing frameshift, premature termination codon (p.Glu383fs) and induced truncated enzymes.

Conclusion: Our experience for stepwise clinical, laboratory and molecular approach would be helpful to diagnose these patients accurately and understand the genetic events in 17α-hydroxylase/17,20-lyase deficiency patients.