Genetic testing of chorionic villi from abortuses during early pregnancy / 中华医学遗传学杂志

OBJECTIVE@#To explore the prevalence and characteristics of chromosomal abnormalities in abortuses during early pregnancy with single nucleotide polymorphism microarray (SNP-array).@*METHODS@#For 520 abortuses, copy number variations (CNVs) in chorionic villi were analyzed with SNP-array.@*RESULTS@#In 510 (98.1%) of the samples, the analysis was successful. Among these, 57.6% (294/510) of the samples were found to harbor clinically significant chromosomal abnormalities. 38.8% of the samples (198/510) had a normal result. 2.4% (12/510) of the samples harbored benign CNVs, and 1.2% (6/510) harbored variants of uncertain significance (VOUS). Aneuploidies, polyploidies, pathogenic CNVs and uniparental disomies (UPD) had accounted for 75.2% (221/294), 13.9% (41/294), 8.2% (24/294), and 2.7% (8/294) of the samples, respectively. 45,XO was the most common finding, which was followed by trisomy 16 and trisomy 22. 69,XXY was the most common polyploidy.@*CONCLUSION@#Chromosomal abnormalities are the main cause for early miscarriage, among which aneuploidies are most common. The prevalence of aneuploidies is significantly increased among women over 35. SNP-array analysis has the advantage of high success rate, high resolution and great accuracy, but the clinical significance of microdeletions/microduplications found by SNP-array can be difficult for interpretation.

Analysis of non-invasive prenatal screening detection in fetal chromosome aneuploidy / 中华妇产科杂志

Objective To evaluate the efficacy of non-invasive prenatal screening (NIPS) in the detection of fetal aneuploidies.Methods Cell free DNA was sequenced in 5 566 pregnant women to identify the fetal aneuploidies in the First Affiliated Hospital of Zhengzhou University from January 1st,2015 to March 15th,2016.Among them,5 230 (93.96％,5 230/5 566) were singleton pregnancies and 336 (6.04％,336/5 566) were twin pregnancies.In singleton pregnancies,1 809 (34.59％,1 809/5 230) were women with advanced maternal age,and 3 421 (65.41％,3 421/5 230) were young women.The positive results of NIPS were validated by karyotyping through invasive procedures and neonatal outcomes were followed up by telephone.Results Among the 5 566 women,69 (1.24％,69/5 566) got positive NIPS results,with 66 in singleton pregnancies and 3 in twin pregnancies.Two were monochorionic diamniotic twins and 1 was dichorionic twin pregnancy.The positive predictive value of NIPS for trisomy 21,18 and 13 were 100.0％,90.9％ and 100.0％,and was 55.6％ for sex chromosome aneuploidies.There was no false negative case found during the follow-up.In the advanced maternal age group and young women group,the prevalence rates of fetal chromosomal aneuploidies were 1.11％ (20/1 809) and 0.94％ (32/3 421),respectively.In the young women with soft markers in fetal ultrasound,the prevalence of fetal chromosomal aneuploidies was 1.44％ (7/487),and in serum high risk women,it was 0.94％ (7/747).In women with the serum screening risk with cut-off value,0.89％(9/1 016) had fetal aneuploidies,and the prevalence was 0.77％(9/1 171) in volunteers.There was no statistically significant difference among these groups (P=0.636).Conclusions There is no difference in the detection rate of fetal aneuploidies between high-risk women in serum screening and volunteers in NIPS.NIPS is more suitable as a first line screening test for women without fetal ultrasound abnormalities.It should be used carefully when there is ultrasound abnormalities.

"Ethical Consideration about the Technology of ""Three-parent Test Tube Baby""" / 中国医学伦理学

Three-parent test tube baby technology is important to solve the mitochondrial genetic disease.Once available,it raises greatly ethical controversy such as breaking traditional family values,hitting the religious belief,existing unknown risks,correctly handling the failed embryo,as well as the influence on the social status of the babies.Regarding these controversy,we can discuss it from several aspects.Because the development of ethics is behind the progress of science and technology,we should affirm the value of three-parent test tube baby technology and balance the development of science and technology with respecting the religious beliefs.Strict supervision system and standard application system reflect our respect for life.Incomprehension to the unknown things should become the motivation of our inquiry.We should face up to our fear of three-parent test tube baby technology,and thus to strengthen research and deepen understanding.Based on the above argument,this paper puts forward the ethical principles that should be followed in the development of three-parent test tube baby technology,namely respect,benefit,no harm and justice.

Development of Gene Therapy and Its Ethical Reflection / 中国医学伦理学

Since CRISPR/Cas9 has been discovered,it opens a new era for gene therapy with its low cast,high efficiency,short cycle,easy operation and other characteristics.In 2015,Huang Junjiu had used the technique to nodify human embryonic cell for the first time,leading to widespread attention at home and abroad.For nearly 50 years,ethical discussion of gene therapy has never stopped.Through reviewing the development of gene therapy,this paper analyzed several key issues of ethical controversy in gene therapy,such as safety,effectiveness,justice,right,interest orientation and so on,and put forward that gene therapy and ethics are not two opposite sides and cannot be treated separately,the development of gene therapy should follow certain ethical norms and technical norms and it should use the bioethical principles to direct gene therapy.

IDUA gene mutation analysis and prenatal diagnosis of two families affected with mucopolysaccharidosis type I / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To analyze mutations of IDUA gene in two pedigrees affected with mucopolysaccharidosis type I and provide prenatal diagnosis for them.</p><p><b>METHODS</b>The 14 exons of the IDUA gene were subjected to PCR amplification and Sanger sequencing.</p><p><b>RESULTS</b>For pedigree 1, the proband was found to harbor compound heterozygous mutations c.46-57delTCGCTCCTGGCC (p.Ser16_Ala19del) of exon 1 and c.1147delC (p.Arg383Alafs*57) of exon 8 of the IDUA gene, which were inherited from his father and mother, respectively. The latter was unreported previously. Prenatal diagnosis suggested that the fetus has carried a heterozygous c.46-57delTCGCTCCTGGCC mutation. For family 2, the proband was also found to carry compound mutations of the IDUA gene, namely c.721T to C (p.Cys241Arg) of exon 6 and c.1491delG (p.Thr497fs27) of exon 8, which were inherited from her mother and father, respectively. Neither mutation was reported previously. Prenatal diagnosis suggested that the fetus has carried a heterozygous c.721T to C mutation.</p><p><b>CONCLUSION</b>Mutations of the IDUA gene probably underlie the MPS-I in both pedigrees. Above results have enriched the spectrum of IDUA gene mutations and facilitated prenatal diagnosis for both families.</p>

MUT genetic analysis in isolated methylmalonic acidemia pedigrees and its application in prenatal diagnosis / 中华围产医学杂志

Objective To analyze the mutation of MUT with Sanger sequencing technology to explore the feasibility of its application in prenatal diagnosis.Methods MUT sequencing was performed in 24 pedigrees who had history of isolated methylmalonic acidemia (MMA) babies and came to the First Affiliated Hospital of Zhengzhou University and Newborn Screening Center of Maternal and Child Health Hospital of He'nan Province between October 2012 and June 2015 for genetic counseling.Meanwhile,another 100 cases of normal controls also had their MUT gene sequence analyzed.After confirming the genotype of each pedigree,we collected the villi of nine high-risk fetuses in nine pedigrees whose parents were prepared for prenatal diagnosis.Results Totally,25 kinds of MUT gene mutations were identified among the 24 isolated MMA pedigrees,in which 11 were novel mutations including one nonsense mutation [c.616C＞T(p.Q206X)],six missense mutations [c.613G＞A(p.E205K),c.894T＞G(p.1298N),c.1009T＞C(p.F337L),c.1154G＞T(p.L385W),c.1663G＞A(p.A555T) and c.1675G＞A(p.R559G) and four frame shift mutations [c.626-627insC(p.P209Pfs*2),c.755-756insA(p.H252Qfs*6),c.756-757insA(p.M253Nfs*5) and c.1581-1582insA(p.A528Ifs*4)].None of the above mutations was detected in the controls.Finally,among the nine pedigrees for prenatal diagnosis,two were determined to have normal MUT gene,four were found to be heterozygous mutation carriers of MUT gene and three were confirmed as complex heterozygous or homozygous mutation carriers.Families of fetus who had normal MUT gene or fetuses who were carriers chose to continue the pregnancy,while those who had heterozygous mutation of MUT gene chose termination.The results of follow-up of newborns were consistent with that of prenatal diagnosis.Conclusions We found two novel mutations in MUT gene that might lead to isolated MMA.And Sanger sequencing technology for MUT gene sequencing analysis might effectively avoid the birth of isolated MMA children.

MMACHC gene mutation analysis in the prenatal diagnosis of methylmalonic aciduria with homocystinuria / 中华检验医学杂志

Objective To analyse MMACHC mutations for 45 pedigrees with combined methylmalonic aciduria and homocyctinuria by Sanger sequencing, and to discuss the utility of prenatal genetic diagnosis for these pedigrees.Method Peripheral blood was collected from 45 probands and their parents from 2012-2015 in Genetic Counselling Clinic of the First Affiliated Hospital of Zhengzhou University, and the DNA were extracted from the blood.Then the coding sequence of MMACHC gene was amplified by PCR, and the PCR products were further sequenced to detect mutations for each pedigree.For 12 families, chorionic villus sampling was performed on the pregnant women to make prenatal genetic diagnosis.Result There were 14 distinct mutations detected in the 45 pedigrees, and the most frequent mutations are c.609G>A(W203X),c.658-660delAAG(K220del)and c.80A>G (Q27A).Two of those mutations have not been reported before:one is a splicing site mutation c.81+1G>A;while the other is a missense mutation c.665A>G,p.Y222C.Most mutations were found in exon 4.Among the 12 pedigrees who received prenatal diagnosis, 2 fetuses were normal, 7 fetuses were carriers of heterozygous mutation, and the other 3 fetuses were patients with compound heterozygous mutation or homozygous mutation.The couples whose fetuses were normal or carriers continued the gestation, while the couples whose fetuses were patients decided to terminate the pregnancy.After delivery, the outcome of the fetuses was the same as the prenatal diagnose results.Conclusion Two novel mutations of MMACHC were identified and prenatal genetic diagnosis helps to avoid the delivery of combined methylmalonic aciduria and homocyctinuria patients.