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_...     

1例智力障碍合并癫痫家系基因变异分析及产前诊断

目的:对1例智力障碍合并癫痫的患儿及其家系进行分子遗传学检测,明确其致病原因,为产前诊断提供依据。方法:应用全外显子测序技术寻找患儿的致病变异,使用Sanger测序技术对患儿及其家系进行致病位点验证,并通过羊水穿刺和Sanger测序为患儿母亲提供产前诊断和遗传咨询。结果:全外显子测序和Sanger验证结果表明,患儿DYRK1A基因存在c.504dupT(p.D169*fs*1)杂合突变,其父母该位点均为野生型,为新发突变。对患儿母亲羊水样本进行检测,胎儿DYRK1A基因c.504位点未检测到变异。结论:全外显子测序技术检测到DYRK1A基因c.504dupT导致的常染色体显性遗传性智力障碍7型可能是该患儿的致病原因,有助于对该家系进行遗传咨询和产前诊断,同时丰富了该致病基因的变异谱。     

应用Ion Torrent半导体测序检测马凡综合征患者FBN1基因致病突变

目的:对3个马凡综合征(MFS)家系及1例MFS患者的原纤维蛋白1基因(FBN1)进行基因检测,以明确致病突变,为患者提供遗传咨询及产前诊断。方法:应用高通量Ion Torrent半导体测序技术对3个MFS家系的先证者及1例MFS患者的FBN1基因进行检测,筛选致病突变位点,并用Sanger测序法验证。对1例胎儿FBN1基因相应的位点进行检测,以明确其受累情况。结果:患者P1 FBN1基因检测到c.7125_7126 del TG杂合性缺失突变,为可疑致病位点;家系1患者FBN1基因检测到IVS 27-1G>C(c.3464-1G>C)杂合性突变,为致病突变;家系2患者FBN1基因检测到c.4981G>C(p.Gly1661Arg)杂合性错义突变,为致病突变,胎儿携带同样突变;家系3患者FBN1基因检测到c.1546C>T(p.Arg516Term)杂合性无义突变,为致病突变。结论:应用高通量Ion Torrent半导体测序技术检测到3个MFS家系及1个MFS患者的致病基因突变,为临床诊断及遗传咨询提供分子遗传学依据,并对1例胎儿进行了产前诊断。     

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。     

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。     

Ⅰ型神经纤维瘤病1家系的胚胎植入前遗传学检测及产前诊断

本文报告了一个Ⅰ型神经纤维瘤病（type Ⅰ neurofibromatosis,NF1）家系的胚胎植入前遗传学检测及产前诊断经过。采用高通量测序技术结合多重连接酶探针依赖扩增技术对该家系进行基因检测,明确致病变异位点,并用Sanger测序进行致病变异位点验证,发现先证者及其患病母亲均存在 NF1基因c.4...     

应用变性高效液相色谱技术检测结节性硬化症TSC1基因外显子15基因突变的研究

摘要：目的　探讨结节性硬化症（TSC）TSC1基因外显子15基因突变的特点。方法　1996—2006年采用多聚酶链扩增和变性高效液相色谱（DHPLC）技术,对21个家系59名研究对象进行了TSC1基因外显子15检测,对DHPLC检测异常者再进行多聚酶链扩增产物直接测序方法证实其突变类型。结果　对21个家系TSC1 基因外显子15共检测出4个家系的3种突变形式,其中c.1708～1709delAG（p.Arg570GlyfsX17）与c.1888～1891delAAAG（p.Lys630GlnfsX22） 两种突变为国内尚未报道的小的缺失突变,c.1460C > G（p.Ser487Cys）突变为1种罕见的错义突变。TSC1 基因外显子15突变基因检出频率为4/21（19%）。在检出突变的4个家系中1个为家系突变,其余3个为散发突变。结论　TSC1基因外显子15的c.1460C > G（p.Ser487Cys）,c.1708～1709delAG（p.Arg570GlyfsX17）与c.1888～1891delAAAG （p.Lys630GlnfsX22） 突变为目前国内首报突变。     

3例家族性Alport综合征遗传咨询和产前诊断的临床病例分析

目的:利用高通量测序(NGS)技术分析家族性Alport综合征(AS)的致病性突变及遗传方式,为咨询者提供准确的遗传咨询并给予产前诊断。方法:对3例家族性AS先证者进行致病性突变分析及家系验证,对遗传咨询者进行产前诊断。结果:3例先证者均发现AS致病基因COL4A5点突变,突变位点分别位于c2633G→A、c1769A→C、c1352G→A,经家系验证均为致病性突变。对3例咨询者胎儿DNA进行Sanger验证(第一代DNA测序技术),提示1例胎儿携带AS致病基因COL4A5的错义突变,2例未检测出致病性突变。结论:认识AS遗传方式的多样性和遗传特征,强调重视先证者的基因诊断及家系验证,确定遗传方式,建议行遗传咨询并给予生育指导。     

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。     

软骨发育不全的产前基因诊断

目的:探讨采用成纤维细胞生长因子受体3(FGFR3)基因测序技术对软骨发育不全(achondroplasia,ACH)进行产前诊断的价值,以为遗传咨询和临床干预提供依据。方法:选择8个ACH家系,其中5个家系中母方为ACH,1个家系父母双方都是ACH,2个家系父母双方正常曾生育过ACH患儿。提取患者及家庭其他成员外周血基因组DNA,应用基因测序对FGFR3基因进行检测;抽取胎儿羊水或脐血,提取基因组DNA后对FGFR3基因进行检测。对超声检查胎儿发现短肢发育异常的4个胎儿进行产前基因诊断。结果:5个家系都是母方c.1138GA杂合型突变,产前基因诊断3个胎儿(其中1个家系是2次妊娠)是c.1138GA杂合型,3个胎儿正常;1个家系父母双方都是c.1138GA杂合型突变,胎儿也是c.1138GA杂合型突变;2个家系父母双方正常而生育的患儿是c.1138GA杂合型突变,再次妊娠的胎儿都正常。4个短肢发育异常胎儿,基因检测均未发现突变。4个c.1138GA杂合型突变胎儿和4个短肢发育异常胎儿均已引产;5个未发现突变的胎儿已分娩,随访均为健康个体。结论:FGFR3基因检测可为ACH患者或生育过ACH的家庭提供遗传咨询和产前基因诊断。     

Implications of multigene testing for hereditary breast cancer in primary care

Approximately 1 in 8 women will develop breast cancer during their lifetime and the risk factors include age, family history, and reproductive factors. In women with a family history of breast cancer, there is a proportion in which a gene mutation can be the cause of the predisposition for breast cancer. A careful assessment of family and clinical history should be performed in these women in order to determine if a genetic counseling referral is indicated. In cases of hereditary breast cancer, genetic testing with a multigene panel can identify specific genetic mutations in over 100 genes. The most common genes mutated in hereditary breast cancer are the high-penetrance BRCA1 and BRCA2 genes. In addition, other mutations in high-penetrance genes in familial cancer syndromes and mutations in DNA repair genes can cause hereditary breast cancer. Mutations in low-penetrance genes and variants of uncertain significance may play a role in breast cancer development, but the magnitude and scope of risk in these cases remain unclear, thus the clinical utility of testing for these mutations is uncertain. In women with high-penetrance genetic mutations or lifetime risk of breast cancer > 20%, risk-reducing interventions, such as intensive screening, surgery, and chemoprevention, can decrease the incidence and mortality of breast cancer.     

Outcomes of screening endometrial cancer patients for Lynch syndrome by patient-administered checklist

Objective

The aims of this study were to implement a patient-administered checklist designed to identify endometrial cancer patients at elevated risk for Lynch syndrome; measure subsequent genetic counseling and testing; and identify differences between those who attended genetic counseling and those who did not.

Methods

We developed a 4-item yes/no checklist of personal and family history risk factors for Lynch syndrome-associated endometrial cancer and recommended referral for genetic counseling for patients meeting any of the criteria. Retrospective chart review was performed to determine subsequent genetic counseling and testing outcomes over a 15 month period.

Results

6/387 (1.6%) of endometrial cancer patients tested positive for a Lynch syndrome mutation. 4/24 (17%) of endometrial cancer patients who met referral criteria and attended genetic counseling tested positive. 38/70 (55%) of patients who met referral criteria were not seen for genetic counseling. Patients who were diagnosed with endometrial cancer at younger ages, who had primary surgery at our institution, or who met more than one referral criteria were more likely to be seen for genetic counseling.

Conclusions

Endometrial cancer patients who met referral criteria and attended genetic counseling comprised a population enriched for Lynch syndrome. This approach allowed Lynch syndrome evaluation resources to be targeted to a population of patients that is high risk and interested in the information. The referral rate of at-risk patients needs to be improved, and allocating resources towards this goal could increase the identification of Lynch syndrome while avoiding some of the pitfalls of universal screening.     

Prenatal diagnosis of oculocutaneous albinism type II and novel mutations in two Chinese families

OBJECTIVE: The prenatal genetic diagnosis and counseling of oculocutaneous albinism type II (OCA2) by detecting mutations in the OCA2 gene METHODS: DNA samples were extracted from peripheral whole blood and amniocentesis-derived cells. Polymerase chain reaction and automatic sequence analysis were used to screen the OCA2 gene. RESULTS: Case 1: Two novel heterozygous mutations (p.N476D and p.Y827H) in the P gene were detected in the proband. Molecular prenatal diagnosis on fetal DNA revealed N476D. The pregnancy progressed uneventfully to a normal outcome. Case 2: Mutation analysis of the DNA of family 2 revealed compound heterozygosities for two novel P gene mutations (p.N476D and p.G775R). The pregnant female and the fetus each presented with a single P gene mutation (p.V443I and G775R, respectively). The pregnancy was continued. CONCLUSION: This is the first report of prenatal diagnosis performed in families with oculocutaneous albinism type II (OCA2). Also, this report reveals three novel mutations of the P gene.     

中国南方妇女子宫内膜异位症与人类白细胞抗原-DQA1等位基因相关性的研究

目的 探讨子宫内膜异位症（内异症）与人类白细胞抗原－DQA1（HLA－DQA1）位点等位基因的相关必琢内异症患者的遗传易感性。方法 用聚合酶链反应－序列特异性引物（PCR－SSP）技术,对51例经腹腔镜或手术证实为内异症的患者（内异症组）和44例非内异症的妇女（对照组）进行HLADQA1等位基因的基因分型。结果 HLA－DQA1＊0401基因频率内异症组（12％）明显高于对照组（0％）（P＝0．019）,而HLA－DQA1＊0301基因频率在内异症组（14％）明显低于对照组（39％）（P＝0．005,比值比＝0．253）。结论 HLA－DQAQ＊0401基因与内异症的遗传易感性相关,而HLA－DQA1＊0301基因可能是内异症的保护基因。     

A follow-up study in a Taiwanese family with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes syndrome.

BACKGROUND/PURPOSE: MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes) syndrome is often associated with A3243G point mutation of mitochondrial DNA (mtDNA). We previously described a MELAS family characterized by harboring an additional approximately 260 bp tandem duplication in the D-loop and a novel C3093G point mutation in the 16S rRNA gene of mtDNA in the proband. We studied the clinical progression and fluctuation of mtDNA mutations in this Taiwanese MELAS family. METHODS: We followed up the clinical course in all members of this family (1 proband, her mother and 3 sons) for 12 years. Mutations of mtDNA in serial muscle biopsies of the proband and blood samples and hair follicles taken at different time points from the members of this family were analyzed. RESULTS: The proband developed repeated stroke-like episodes, chronic intestinal pseudo-obstruction, polyneuropathy, progressive renal failure and dilated cardiomyopathy with heart failure. During the follow-up period, the mother and one of the siblings of the proband developed stroke-like episodes at age 62 and 12, respectively. There was no significant difference in the proportions of mtDNA with A3243G mutation among five serial muscle biopsies of the proband. In one carrier (I-2), the proportion of A3243G mutated mtDNA in blood cells was slightly increased with disease progression. CONCLUSION: This study underlines the importance of early detection of extraneuromuscular symptoms in the members of a family with MELAS syndrome by adequate follow-up. The age of onset of stroke-like episode in MELAS syndrome may be as late as 62 years. We suggest that the manifestations of MELAS syndrome in this family might be associated with the additional approximately 260 bp tandem duplication in the D-loop region and the coexistence of C3093G mutation in the 16S rRNA gene with the A3243G mutation of mtDNA.     

Investigation of the serum glucocorticoid kinase 1 gene in patients with transient tachypnea of the newborn

Abstract

Objective: The aim of this study was to investigate whether there is a role of the serum glucocorticoid kinase (SGK) 1 gene, which has an effect on the control of the epithelial sodium channels.

Materials and method: This study included patients who were diagnosed with transient tachypnea of the newborn (TTN) with more than 37 weeks of gestation. As the control group, healthy newborns of the same gestational age were included. From each group, within the first 5?d of their lives, 2?cc of whole blood was taken in EDTA tubes, and stored at ?80?°C. The DNA extraction was performed.

Results: There were 32 patients in the TTN, and also 32 patients in the control group. The heterozygous allele rs1057293 (3/28) and rs1743966 (8/28) were located in the encoder region of the SGK 1 gene. In addition, in encoding region of the SGK 1 gene, the Arg97Ile (1/28), which causes the amino acid changes, had a genotype frequency of 0.0357, and a mutation was identified in Arg97Ile.

Discussion: We have defined polymorphisms rs1057293 and rs1743966 in the SGK 1 gene, and the Arg97Ile mutation, for the first time in patients with TTN. This pilot study gave us some clues about a genetic basis of TTN phenotype, next to the lack of the pulmonary maturation.     

Consequences of universal MSI/IHC in screening ENDOMETRIAL cancer patients for lynch syndrome

Objective

Determine factors impacting the uptake of genetic counseling and results of genetic testing following universal tumor testing for Lynch syndrome in patients with endometrial cancer.

Methods

The study population consisted of two unselected cohorts of endometrial cancer patients, 408 identified retrospectively and 206 identified prospectively. Immunohistochemistry for mismatch repair protein expression and/or microsatellite instability analysis was performed on these tumors. MLH1 methylation analysis was performed on tumors with loss of MLH1 protein. Tumor studies were considered suggestive of Lynch Syndrome if they showed immunohistochemical loss of MSH2, MSH6 or PMS2, loss of MLH1 without MLH1 promoter methylation, and/or microsatellite instability. Participants with suggestive tumor studies were contacted and offered genetic counseling and testing.

Results

In the retrospective cohort, 11% had tumor studies suggestive of Lynch syndrome, and 42% was seen for genetic counseling. A germline mutation was detected in 40%, and one had a variant of uncertain significance. In the prospective cohort, 8.7% of patients had tumor testing suggestive of Lynch syndrome; 72% were seen for genetic counseling. Germline mutations were found in 40%, and one had a variant of uncertain significance. Common challenges included timing of re-contact, age, perceived lack of relevance, inability to travel and limited insurance coverage.

Conclusions

There are several barriers to genetic counseling and testing follow-up after universal tumor testing, and uninformative genetic test results present a management challenge. It is important to consider these limitations when implementing an approach to screening endometrial cancer patients for Lynch syndrome.     

Intra-amniotic pressure is not affected by amniocentesis between 13 and 18 weeks of gestation

Changes in amniotic fluid pressure before and after amniocentesis fell within the range of ± 5 mmHg, except when uterine contractions were present. Intra-amniotic pressure is not affected by amniocentesis between 13 and 18 weeks of gestation. Amniotic fluid pressure was recorded in 82 pregnancies of patients undergoing genetic amniocentesis to determine whether sampling of amniotic fluid between 13 and 18 weeks changed intra-amniotic pressure. Pressures were recorded through a needle and saline filled catheter with a zero-level at the needle tip. Amniotic fluid pressure was unrelated to gestational age (P = 0.962) during the weeks we performed our measurements. Fluid samples of 12.6% of the total volume in a group of early genetic amniocentesis (n = 65) and of 7.5% of the total volume in a group of late genetic amniocentesis (n = 17) did not change significantly amniotic fluid pressure values. An increase in pressure of more than 5 mmHg only occurred in cases where uterine contractions were present. Other than these cases, all pressure change values fell within the range of ± 5 mmHg. No difference in pregnancy outcome were present within the two groups. An argument for a standard method for stationing pressure is presented.     

A family study of complex chromosome rearrangement involving chromosomes 1, 8, and 11 and its reproductive consequences

Complex chromosome translocations are structural chromosomal rearrangements involving three or more chromosomes and more than two breakpoints. A complex chromosome rearrangement was detected in a phenotypically normal female patient that was referred to the hospital for genetic counseling due to reproductive failure. A cytogenetic evaluation was performed, according to standard method of chromosomal analysis, using G-banding technique. The patient’s karyotype showed a balanced complex chromosome rearrangement (BCCR) involving chromosomes 1, 8, and 11 with three breakpoints 1p31, 8q13, and 11q23. The karyotype designed according to ISCN (2013), is 46,XX,t(1;8;11)(p31;q13;q23) (8qter→8q13::1p31→1qter;8pter→8q13::11q23→11qter;11pter→11q23::1p31→1pter). Additionally, the proband’s mother and brother were tested, resulting in the same exact translocation. In this study, we describe all possible meiotic segregations regarding this translocation, as well as the clinical phenotypes which could arise, if unbalanced products of conception survive. This is a rare case of familial complex chromosome rearrangement, giving a view for its reproductive consequences.