To assess the value of non-invasive prenatal testing (NIPT) for the screening of fetal chromosomal abnormalities. For 12 085 pregnant women, the results of NIPT and invasive prenatal diagnosis were compared. The test was successful in 12 067 cases and has detected 179 chromosomal abnormalities, with a positive rate of 1.48%, sensitivity of 98.39% and specificity of 99.02%. Invasive prenatal diagnosis was performed for 3 of 18 patients who had failed NIPT but has detected no karyotypic abnormality. Except for one case of twin Cesarean section which delivered a normal female fetus and a stillbirth of unknown sex, the remainder of the 18 cases all had a normal delivery. The positive rate of NIPT screening for the abnormal ultrasound group was significant higher than that other groups (P< 0.01). Among those with positive results of NIPT, 122 underwent invasive prenatal diagnosis, and 25 trisomy 21, 7 trisomy 18, 3 trisomy 13, 4 aneuploidies of other autosomes, 13 sex chromosomal aneuploidies and 9 microdeletion/microduplications were confirmed, which yielded a positive predictive rate of 86.21%, 50.00%, 23.08%, 21.05%, 46.43%, and 47.36%, respectively. NIPT has high sensitivity, specificity and positive predictive value, and is an effective method for prenatal screening. In addition to chromosomes 21, 18 and 13, NIPT has certain predictive value for other autosomal aneuploidies, sex chromosomal aneuploidies, microdeletion/microduplications, and can provide a reference for karyotype analysis and chromosomal microarray verification.

To determine the carrier rate of Fragile X mental retardation 1 gene (FMR1) mutants in women with a history of adverse pregnancy or childbirth, and to provide prenatal diagnosis for the carriers. Peripheral blood samples were collected from women with a history of adverse pregnancy or childbirth, and the FMR1 gene cytosine-guanine-guanine repeat number (CGG)n was determined by triple-repeat primer polymerase chain reaction (TP-PCR) combined with capillary electrophoresis. Prenatal diagnosis was provided for the carriers during pregnancy. Among 819 samples, 9 gray zone repeats carriers and 10 premutation carriers were detected, which gave a prevalence of 1 in 91 and 1 in 82, respectively, with a total prevalence of 1 in 43. Prenatal diagnosis was provided during 7 pregnancies for 6 carriers. A female fetus with premutation (n = 30/57) and an affected male fetus with full mutation (n = 336) were detected. FMR1 gene testing in women with a history of adverse pregnancy or childbirth can facilitate genetic counseling and reproductive guidance for carriers of gray zone repeats and premutations. Prenatal diagnosis for carriers of premutation can facilitate reduction of the birth of children with fragile X syndrome.

To retrospectively analyze non-invasive prenatal screening (NIPS) data from two centers. The NIPS results of 10 840 samples were analyzed, including 21/18/13 trisomies (T21/T18/T13), sex chromosome and other autosomal aneuploidies, and copy number variants (CNVs). The maternal age, gestational week, body mass index and concentration of free fetal DNA (cffDNA) were also analyzed. The average gestational age of the 10 840 pregnant women was (32.34±5.04) year old, and the average gestational week for NIPS was (17.60±3.55) week. The overall false positive rate for T21/T18/T13 was 0.11%, sensitivity was 100%, specificity was 99.89%, and positive predictive value was 81.5%. The positive predictive values for sex chromosome and other autosomal aneuploidies and CNVs were 56.67%, 11.76% and 83.33%, respectively. The incidence of T21/T18 in the elder women (35 years or elder) was 2.12 times(P<0.01) and 1.81 times (P> 0.05) that of young women. cffDNA was in proportion to gestational week (r = 0.207) and in inverse proportion to body mass index (r = -0.177). It has increased slowly before 15 weeks of gestation and thereafter at a rate of 0.5% per week after the 16th week. The performance of NIPS in this study is by large close to the reported in the literature, and the results can provide a reference for further study.

To analyze the phenotype and genetic variants of a pedigree affected with hereditary protein C (PC) deficiency. The protein C activity (PC:A) of the proband and her family members (a four-generation pedigree including 11 individuals) were tested by chromogenic substrate method, and the protein C antigen (PC:Ag) was detected with an enzyme-linked immunosorbent assay(ELISA). The 9 exons and flanking sequences of the protein C (PROC) gene were amplified by PCR and directly sequenced. Suspected mutation was validated by clone sequencing and in other members of the family. MutationTaster and ClustalX-2.1-win was used to analyze the pathogenicity and conservation of the mutation site,respectively. Three-dimentional protein model and amino acids interaction were analyzed with Swiss-PdbViewer software. The PC: A and PC: Ag of the proband were decreased to 46% (reference range: 70%-130%) and 50% (referencerange:70%-140%), respectively. Her grandmother,aunt, cousin and younger brother also showed declined PC:A and PC:Ag by approximately 50%. Genetic analysis revealed that the above individuals have all carried a deletional mutation c.1212-1212delG (p.Met364TrpfsX15) in exon 9 of the PROC gene which can cause replacement of Methionine at position 364 by Tryptophan and alteration of 15 downstream amino acids, and produce a premature stop codon at position 378. The score of MutationTaster was 1.000, indicating that the variant is pathogenic. Conservative analysis showed that the 15 altered amino acids are located in a conserved region across nine homologous species. Protein model analysis showed that the mutation has disrupted a catalytic domain of protein C thereby affected its function. The heterozygous c.1212-1212delG deletional mutation in exon 9 of the PROC gene, which was unreported previously,probably accounts for the decrease of PC:A and PC:Ag in this pedigree.

To explore the value of in situ amniocyte culture for prenatal diagnosis. 2716 amniotic fluid samples were cultured in situ on slides. After the culture, the slides were stained, photographed and analyzed. All samples were successfully analyzed, with the success rates for primary culture and subculture being 98.42% and 1.58%, respectively. 224 samples (8.25%) were detected with chromosomal aberrations, which included 125 cases with trisomy 21, 31 with trisomy 18, 3 with trisomy 13, 4 with 45,X, 17 with 47,XXY, 5 with 47,XYY, 1 with 48,XXY,+18, 1 with 48,XXYY, 26 with structural chromosomal aberrations, and 11 with mosaicisms for aneuploidies. In situ amniocyte culture is stable and has a high success rate, and is capable of identifying true and false mosaicisms, which can improve the accuracy of prenatal diagnosis.

To analyze the clinical and molecular characteristics of a child with very long chain acyl-CoA dehydrogenase deficiency (VLCADD). Peripheral blood sample of the patient was collected for the extraction of genomic DNA. Next generation sequencing (NGS) was carried out for the proband. Suspected mutations were validated by Sanger sequencing. The patient, a 12-month-old girl, was admitted for diarrhea, vomiting, fever, poor spirit and decreased blood pressure. During the course of the disease, she also manifested hypertrophic cardiomyopathy, cardiogenic shock, elevated myocardial enzyme kinase, fever and metabolic acidosis, and had died after three days due to ventricular tachycardia and respiratory failure. Genetic testing showed that she has carried heterozygous mutations of of the ACADVL gene, namely c.664G>A (exon 8) and c.1056_1057del (exon 10). Blood screening for metabolic genetic diseases showed increased C12, C14, C16, C18, C14:1, C14:2, C16:1, C4/C3 and C8/C3, accompanied with decreased C0, C0/C16 and C8/C10. VLCADD and secondary carnitine deficiency could not be excluded, which was in keeping with the result of genetic testing. The child was diagnosed with VLCADD, which may be attributed to the compound heterozygous c.664G>A and c.1056_1057del variants of the ACADVL gene.

To explore the clinical features and molecular basis of a Chinese pedigree with two siblings affected by cytochrome P450 oxidoreductase deficiency (PORD). Clinical features of the patients were reviewed, and their genomic DNA was subjected to next generation sequencing (NGS). The two siblings presented peculiar facies, genital hypoplasia and skeletal deformity. NGS revealed that both have carried compound heterozygous variants of the POR gene, namely c.1370G>A and c.517-19_517-10delGGCCCCTGTGinsC, which were respectively inherited from their parents. Both siblings were diagnosed with PORD based on sequencing of the POR gene. The newly discovered POR c.517-19_517-10delGGCCCCTGTGinsC has enriched the spectrum of PORD-related genetic variants.

To analyze the action of miRNA-326 on its target gene BCL-XL and the molecular mechanism of platelet apoptosis regulated by miRNAs. Dual-luciferase vectors containing respectively the wild-type and mutant 3'-untranslated region (3'UTR) fragments of the BCL-XL gene were constructed with firefly and renilla luciferases and transfected into 293T cells. Relative fluorescence intensities of the transfected cells were measured. Dual-luciferase reporter gene vectors for PsiCHECK- BCL-XL -3'UTR-WT (wild-type) and PsiCHECK- BCL-XL -3' UTR-MT (variant) were respectively constructed. Relative fluorescence intensities of the 293T cells co-transfected by miRNA-326 and PsiCHECK- BCL-XL -3'UTR-WT plasmid were significantly lower compared with the control group (co-transfected by a miRNA-326 negative sequence and PsiCHECK- BCL-XL -3' UTR-WT plasmid) ( P = 0.034). The relative fluorescence intensity was also significantly reduced in cells co-transfected by miRNA-326 and PsiCHECK- BCL-XL -3' UTR-WT plasmid compared with the mutant control group co-transfected by miRNA-326 and PsiCHECK- BCL-XL -3'UTR-MT plasmid (P = 0.022). miRNA-326 may participate in the regulation of platelet apoptosis by acting on the 3'-UTR of the BCL-XL gene.

Neurodegenerative diseases are a group of diseases characterized by chronic progressive damage to tissues of central nervous system and peripheral nervous system, which include Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, frontotemporal dementia, etc. The etiology is mainly related to factors such as aging, genetics and environment. More and more evidence indicate that mitochondrial dysfunction plays a vital role in the pathogenesis of neurodegenerative diseases. Variants of mitochondrial genes, including point variants, deletions, and copy number variations, have been recognized as important factors modulating genetic susceptibility to such diseases. This paper has reviewed recent studies for the influence of mitochondrial variants on the pathogenesis of neurodegenerative diseases, in order to provide clues for the pathogenesis, diagnosis and development of new drugs for such disorders.

To explore the genetic basis of a Chinese patient featuring global developmental delay. Peripheral venous blood samples from the proband and his parents and sister were taken for the extraction of DNA. Target capture and next generation sequencing was carried out to detect genetic variants associated with the disease. Suspected variant was validated by Sanger sequencing. Genetic testing discovered that the proband has carried hemizygous c.150G>T and c.150+1G>T variants of the KDM5C gene which are inherited from his mother. His younger sister also carried the variants. The c.150+1G>A variant was unreported previously, which has altered a splice site and was predicted to be pathogenic by bioinformatics analysis. The hemizygous c.150+1G>T variant of the KDM5C gene, known to underlie X-linked Claes-Jensen type syndromic mental retardation, probably accounts for the disorder in the patient. Identification of this variant has enriched the variant spectrum of the KDM5C gene.