Genetic diagnosis of a fetus with Dandy-Walker syndrome / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a fetus with Dandy-Walker malformation.@*METHODS@#G-banding chromosomal karotyping, single nucleotide polymorphism microarray (SNP array) and fluorescence in situ hybridization (FISH) were carried out for the fetus. Chromosomal karyotyping and FISH assay were also carried out for both parents.@*RESULTS@#SNP array has detected a 4266 kb microdeletion at 6p25.3p25.1 in the fetus, which was confirmed by FISH. FISH analysis of the parents demonstrated that the father has carried a cryptic t(6;14) (p25.1;p13) translocation, while the fetus has a der(6)t(6;14)(p25.1;p13) derived the paternal translocation.@*CONCLUSION@#The der(6)t(6;14)(p25.1;p13) probably underlies the Dandy-Walker malformation in the fetus. The 6p25.3p25.1 microdeletion is due to unbalanced gametes produced by the father's cryptic balanced translocation.

Genetic analysis of a child with Sotos syndrome / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a child with mentally retardation.@*METHODS@#G-banding karyotyping, single nucleotide polymorphism array (SNP-array) and fluorescence in situ hybridization (FISH) were performed for the child. Karyotyping and FISH were also carried out for her parents.@*RESULTS@#SNP-array has detected a 5077 kb microdeletion at 5q35.2q35.3 and a 4964 kb microduplication at 7q36.2q36.3 in the child. The results were confirmed by FISH. Based on above results, the father was subsequently found to carry a cryptic t(5;7) (q35.2; q36.2) translocation. The child was verified to have inherited a der(5) t(5;7)(q35.2; q36.2) from her father.@*CONCLUSION@#The 5077 kb microdeletion at 5q35.2q35.3 may have predisposed to the Sotos syndrome in the child. SNP-array combined with G-banding karyotyping and FISH can help to detect cryptic chromosomal translocations among patients.

Genetic diagnosis of a fetus with Dandy-Walker syndrome / 中华医学遗传学杂志

Objective@#To explore the genetic basis for a fetus with Dandy-Walker malformation.@*Methods@#G-banding chromosomal karotyping, single nucleotide polymorphism microarray (SNP array) and fluorescence in situ hybridization (FISH) were carried out for the fetus. Chromosomal karyotyping and FISH assay were also carried out for both parents.@*Results@#SNP array has detected a 4266 kb microdeletion at 6p25.3p25.1 in the fetus, which was confirmed by FISH. FISH analysis of the parents demonstrated that the father has carried a cryptic t(6; 14)(p25.1; p13) translocation, while the fetus has a der(6)t(6; 14)(p25.1; p13) derived the paternal translocation.@*Conclusion@#The der(6)t(6; 14)(p25.1; p13) probably underlies the Dandy-Walker malformation in the fetus. The 6p25.3p25.1 microdeletion is due to unbalanced gametes produced by the father’s cryptic balanced translocation.

Genetic analysis of a mosaic case with low proportion mutation of / 浙江大学学报·医学版

OBJECTIVE@#To perform gene mutation analysis in a patient with atypical clinical manifestations of tuberous sclerosis (TSC) for definite diagnosis.@*METHODS@#Peripheral blood DNA was obtained from a patient with clinically suspected TSC and her parents, and all exons and their flanking sequences of @*RESULTS@#A heterozygous nonsense mutation c.1096G>T (p.E366*) was identified in the exon 11 of the @*CONCLUSIONS@#The somatic mosaic mutation c.1096G>T (p.e366*) may be responsible for the phenotype of TSC in this patient. And the drop digital PCR is expected to be a diagnostic method for somatic cells mosaicism.

Genetic analysis and clinical phenotype of a family with lymphedema-distichiasis syndrome / 浙江大学学报·医学版

OBJECTIVE@#To identify the genetic causes of a family with lymphedema-distichiasis syndrome (LDS).@*METHODS@#The whole exome sequencing was performed in a aborted fetus as the proband, and a candidate gene was identified. Peripheral blood of 8 family members were collected. Genotypic-phenotypic analysis were carried out through PCR amplification and Sanger sequencing.@*RESULTS@#The proband, and the mother, grandmother, uncle, granduncle of the proband all had distichiasis or varix of lower limb carried a @*CONCLUSIONS@#The

Prenatal diagnosis of a fetus with Phelan-McDermid syndrome / 中华医学遗传学杂志

OBJECTIVE@#To diagnose a fetus with Phelan-McDermid syndrome (PMS) using various techniques.@*METHODS@#Single nucleotide polymorphism array (SNP Array), multiplex ligation-dependent probe amplification (MLPA), fluorescence in situ hybridization (FISH) were applied in conjunction for the prenatal diagnosis of the fetus.@*RESULTS@#SNP Array detected a 4.03 Mb microdeletion at 22q13.31q13.33 in the fetus, which was confirmed by FISH and MLPA. FISH analysis of the parents suggested that the 22q13.31q13.33 deletion has a de novo origin.@*CONCLUSION@#Combined use of various techniques can enable accurate prenatal diagnosis and genetic counseling.

Genetic analysis and prenatal diagnosis of a sporadic family with neurofibromatosis type 1 / 浙江大学学报·医学版

OBJECTIVE@#To identify pathogenic mutation for a family with neurofibromatosis type 1(NF1) and provide prenatal diagnosis for them.@*METHODS@#Mutation analysis of the sporadic family with NF1 was performed with target captured next generation sequencing and Sanger sequencing. RNA samples were extracted from the lymphocytes of NF1 patient and her parents. RT-PCR and Sanger sequencing were performed to analyze the relative mRNA expression in the samples. Prenatal diagnosis of the pathogenic mutation was offered to the fetus.@*RESULTS@#A novel splicing mutation c.1260+4A>T in the gene was found in the proband of the family, but was not found in her parents.cDNA sequencing showed that 13 bases inserted into the 3' end of exon 11 in the gene lead to a frameshift mutation. Prenatal diagnosis suggested that the fetus did not carried the mutant.@*CONCLUSIONS@#The : c.1260+4A>T mutation found in the NF1 patient is considered to be pathogenic, which provides information for family genetic counseling and prenatal diagnosis.

Genetic analysis of a family of Van der Woude syndrome / 浙江大学学报·医学版

OBJECTIVE@#To analyze clinical and genetic features of a family affected with Van der Woude syndrome.@*METHODS@#The umbilical cord blood of the proband and the peripheral blood of the parents were used for the whole exon sequencing to find the candidate gene.Peripheral blood of 9 members of the family were collected for Sanger sequencing verification, bioinformatics analysis and genotype-phenotype correlation analysis.@*RESULTS@#The proband was diagnosed with cleft lip and palate by ultrasound. His father and grandmother had hollow lower lip and all other family members did not have the similar phenotype. A missense c.263A>G (p.N88S) mutation was found in exon 4 of gene in the proband, his father and his grandmother.The mutation was not found in other family members.@*CONCLUSIONS@#A missense c.263A>G (p.N88S) mutation in gene probably underlies the pathogenesis of Van der Woude syndrome in the family and the mutation has been firstly discovered in China.

Genetic analysis of a fetus with multiple malformations caused by complex translocations of four chromosomes / 浙江大学学报·医学版

OBJECTIVE@#To conduct genetic analysis in a fetus with complex translocation of four chromosomes.@*METHODS@#G-banded chromosome karyotype analysis, single nucleotide polymorphism array (SNP array) and fluorescence hybridization (FISH) were performed in a fetus with multiple malformations. Peripheral blood chromosome karyotype and FISH were also carried out for the parents.@*RESULTS@#The fetal amniotic fluid karyotype was 46, XY, t(12; 13)(q22; q32). SNP array analysis showed that there were 20 192 kb duplication at 1q42.13q44 and 13 293 kb deletion at 15q26.1q26.3 in the fetus. The results of karyotype and SNP array were inconsistent. FISH analyses on the parental peripheral blood samples demonstrated that the mother was a cryptic 46, XX, t(1; 15)(q42.1; q26.1) translocation. The fetus had inherited 46, XY, t(12; 13)(q22; q32) from his father and der(15)t(1; 15)(q42.1; q26.1) from his mother.@*CONCLUSIONS@#The 1q42.13q44 duplication and 15q26.1q26.3 deletion may have contributed to the abnormal sonographic features of the fetus. The combination of cytogenetic, SNP array and FISH techniques was beneficial for providing an accurate genetic counseling.

Noninvasive prenatal screening for twin pregnancy: an analysis of 2057 cases / 浙江大学学报·医学版

OBJECTIVE@#To analyze the results of noninvasive prenatal screening (NIPS) for fetal chromosome aneuploidy in twin pregnancy.@*METHODS@#A total of 2057 women with twin-pregnancy between 12-26 weeks were recruited from Women's Hospital, Zhejiang University School of Medicine, Hangzhou Municipal Women's Hospital and Jiaxing Maternal and Child Health Hospital during February 2015 to August 2018. The cell-free DNA was extracted from the peripheral blood sample for DNA library, and non-invasive prenatal testing (NIPT) was performed by high-throughput sequencing technique. The fetal karyotype analysis or neonatal karyotype analysis was performed in pregnant women with fetal chromosome aneuploidy, and all subjects were followed up. The efficiency of NIPS testing for twin aneuploidy was calculated.@*RESULTS@#NIPS revealed chromosome abnormalities in 11 out of 2057 twin pregnant women, 9 cases were confirmed chromosome abnormalities, 2 cases were normal and no false negative cases. In this screening, the detection rate, sensitivity, specificity, positive predictive value, false positive rate of NIPS were 100.00%, 100.00%, 99.90%, 81.82%, 0.10%. Those were 100.00%, 100.00%, 99.95%, 87.50% and 0.05% for trisomy 21, 100.00%, 100.00%, 100.00%, 100.00%, 0.00% for trisomy18, and the specificity and false positive rate for trisomy13 were 99.95% and 0.05%, respectively.@*CONCLUSIONS@#NIPS can detect fetal chromosomal aneuploidy rapidly and accurately in twin pregnancies,and it is of value in clinical application.

Single nucleotide polymorphism microarray in prenatal diagnosis of fetuses with absent nasal bone / 浙江大学学报·医学版

OBJECTIVE@#To assess the clinical application of single nucleotide polymorphism microarray (SNP array) in prenatal genetic diagnosis for fetuses with absent nasal bone.@*METHODS@#Seventy four fetuses with absent nasal bone detected by prenatal ultrasound scanning were recruited from Women's Hospital, Zhejiang University School of Medicine during June 2015 and October 2018. The chromosome karyotypes analysis and SNP array were performed. The correlation between absent fetal nasal bone and chromosome copy number variants was analyzed.@*RESULTS@#Among 74 fetuses, 19 were detected to have chromosomal abnormalities, including 16 cases of trisomy-21, 1 case of trisomy-18 and two cases of micro-deletion/duplication. Among 46 cases with isolated absence of nasal bone, 3 had trisomy-21, and 1 had a micro-duplication. Absence of nasal bone in association with nuchal translucency thickening had a higher rate of abnormal karyotypes compared with isolated absence of nasal bone (=32.27,<0.01).@*CONCLUSIONS@#Fetuses with absent nasal bone and nuchal translucency thickening are likely to have chromosome abnormalities, and SNP array testing is recommended to exclude the chromosome abnormalities.

Application of single nucleotide polymorphism microarray in clinical diagnosis of intellectual disability or retardation / 浙江大学学报·医学版

OBJECTIVE@#To assess the clinical application of single nucleotide polymorphism microarray (SNP array) in patients with intellectual disability/developmental delay(ID/DD).@*METHODS@#SNP array was performed to detect genome-wide DNA copy number variants (CNVs) for 145 patients with ID/DD in Women's Hospital, Zhejiang University School of Medicine from January 2013 to June 2018. The CNVs were analyzed by CHAS software and related databases.@*RESULTS@#Among 145 patients, pathogenic chromosomal abnormalities were detected in 32 cases, including 26 cases of pathogenic CNVs and 6 cases of likely pathogenic CNVs. Meanwhile, 18 cases of uncertain clinical significance and 14 cases of likely benign were identified, no significant abnormalities were found in 81 cases (including benign).@*CONCLUSIONS@#SNP array is effective for detecting chromosomal abnormalities in patients with ID/DD with high efficiency and resolution.

Detection of cell-free fetal DNA in maternal plasma for noninvasive prenatal screening of fetal chromosomal aneuploidies in women of advanced maternal age / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To evaluate the efficiency of cell-free fetal DNA detection as a non-invasive prenatal screening (NIPS) method for women of advanced maternal age.</p><p><b>METHODS</b>A total of 10 584 women of advanced maternal age who received NIPS were recruited from the Women's Hospital, Zhejiang University School of Medicine and Jiaxing Maternal and Child Health Hospital during February 2015 and September 2016. The pregnancy outcome was followed-up. The sensitivity, specificity, positive and negative predictive value of fetal chromosomal aneuploidy detected in NIPS were analyzed. And the relationship between maternal age and fetal common chromosomal aneuploidy was analyzed.</p><p><b>RESULTS</b>The sensitivity, specificity, positive and negative predictive value of NIPS were 100.00%, 99.96%, 91.67%, 100.00% for trisomy 21, 100.00%, 99.93%, 68.18%, 100.00% for trisomy 18, and 100.00%, 99.97%, 25.00%, 100.00% for trisomy 13. High-risk rate and true positive rate of trisomy 21 were positively correlated with the maternal age (all<0.01). There were significant differences in high-risk rate and true positive rate between 35-37 year old groups and 38-40 year old groups (all<0.05). Such difference was also found in high-risk rate between 38-40 year old group and ≥ 41 year old group (<0.05), but not in true positive rate between two groups (>0.05).</p><p><b>CONCLUSIONS</b>NIPS is effective for fetal chromosomal aneuploidy screening in women of advanced maternal age. For women under 38 years of age, NIPS is preferred; for women of 41 and above, invasive diagnostic methods are suggested; and for women between 38-41 years old, the option can be determined by themselves after risks and advantages were fully informed.</p>

Single nucleotide polymorphism-array in genetic analysis of chorionic villi from early spontaneous miscarriages / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To assess the clinical application of single nucleotide polymorphism (SNP)-array in detecting abnormal chromosome karyotypes of chorionic villi from early spontaneous abortuses.</p><p><b>METHODS</b>A total of 861 chorionic villus samples from unexplained early spontaneous abortion were collected from Women's Hospital, Zhejiang University School of Medicine during October 2013 and June 2016, and SNP-array was performed to detect genome-wide DNA copy number variants.</p><p><b>RESULTS</b>All samples were successfully tested by SNP-array and 440 cases (51.10%) were found to have abnormal chromosome constitutions. Aneuploidy was identified in 358 (41.58%) cases, distributing in all chromosomes except chromosome 1. Triploidy and haploidy were found in 21 (2.44%) and one case (0.12%), respectively. Thirty-seven cases (4.30%) were identified as single chromosomal segment deletion or duplication, 25 of which were less than 10 Mb in size. For 6 of 25 cases with unclear pathogenesis, family studies were carried out to identify origin of deletion or duplication, showing that 4 cases were de novo and 2 were inherited from one of the parents. Twenty-three cases (2.67%) showed two chromosomal deletion/duplication segments. Combining with karyotyping and fluorescencehybridization, 6 cases were identified as de novo aberration and 11 carried small-size segmental balanced abnormality.</p><p><b>CONCLUSIONS</b>SNP-array can provide a relatively comprehensive genetic analysis of chorionic villi and can detect various kinds of chromosome abnormalities in spontaneous miscarriages.</p>

Research progress on the safety of offsprings conceived by assisted reproductive technology / 浙江大学学报·医学版

Assisted reproductive technology (ART) employs superovulation,culture and other micromanipulation to complete oocyte maturation, fertilization and early embryo development. Although these techniques have been successfully applied to solve infertility problems, the process may interfere in cell proliferation, differentiation and growth. The clinical and laboratory studies on the safety issue of ART are reviewed in this article. Studies found that the incidence of birth defects increased in ART offspring. Superovulation,culture and intracytoplasmic sperm injection may induce epigenetic aberrations during embryo development, which would influence the development of ART conceived children. The epigenetic susceptibility related to ART might be transmitted to subsequent generations, and the potential impact on ART offspring still need further investigation. In addition, ART treatments may also increase the risk of genetic diseases.