Objective To explore the clinic value of chromosome karyotype analysis of amniotic fluid cells in prenatal diagnosis . Methods 1 466 cases of pregnant women who had the prenatal diagnosis indexes were selected ,and their amniotic fluid specimens were collected through amniocentesis guiding by type‐B ultrasonic around the 16th to 24th week .Amniotic fluid cells were gained after a successful cell culture .G banding was used for the karyotype analysis of amniotic fluid cells .Results The one‐time success rate of cultivation for amniotic fluid cells was 99 .8% .In 1 466 cases of pregnant women ,there were 16 cases of abnormal karyotype polymorphism (including 12 cases of trisomy 21 ,1 case of trisomy 18 ,and 3 cases of Chromosome abnormalities) and 3 cases of chromosomal polymorphism .Conclusion The chromosome karyotype analysis of amniotic fluid cell is still an irreplaceable test in prenatal diagnosis .

OBJECTIVETo detect the pathogenic mutation in a patient with methylmalonic acidemia using IonTorrent Personal Genome Machine (PGM) and assess the feasibility of such technology for analyzing complex monogenic diseases.

METHODSPeripheral blood sample was collected from the patient. Genomic DNA was isolated using a standard method and subjected to targeted sequencing using an Ion Ampliseq Inherited Disease Panel. DNA fragment was ligated with a barcoded sequencing adaptor. Template preparation, emulsion PCR, and Ion Sphere Particles enrichment were carried out using the Ion One Touch system. Data from the PGM runs were processed using Ion Torrent Suite 3.2 software to generate sequence reads. All variants were filtered against dbSNPl37. DNA sequences were visualized with an Integrated Genomics Viewer.

RESULTSAfter data analysis and database filtering, a previously reported nonsense mutation, c.586C>T (p.R196X), and a novel mutation c.898C>T (p.R300X) were identified in the MMAA gene in this patient. Both mutations were verified by conventional Sanger sequencing.

CONCLUSIONPathogenic MMAA mutations have been identified in a patient with methylmalonic acidemia. This new-generation targeted sequencing on the PGM sequencers can be applied for genetic diagnosis of hereditary diseases.

Amino Acid Metabolism, Inborn Errors ; genetics ; High-Throughput Nucleotide Sequencing ; methods ; Humans ; Mutation

Objective To investigate gene mutations in a pedigree with oculocutaneous albinism by using targeted next-generation sequencing technology.Methods Clinical data were collected from a pedigree with oculocutaneous albinism.Genomic DNA was extracted from peripheral blood cells of the proband and his parents.High-throughput sequencing technology was used for sequence analysis of coding regions in exons of 29 genes including TYR,OCA2,TYRP1 and SLC45A2 in the proband to find potential pathogenic gene mutations.Sanger sequencing was conducted to detect the corresponding genetic loci in the parents.Results Two heterozygous mutations were identified in the TYR gene of the proband,including a novel mutation c.534G ＞ C (p.Trp178Cys) and a known mutation c.1147G ＞ A (p.Asp383Asn).The detection of the TYR gene mutations in the parents of the proband showed that the c.534G ＞ C and c.1147G ＞ A mutations in the proband were inherited from his father and mother respectively.Conclusion A novel pathogenic mutation c.534G ＞ C in the TYR gene is identified in the pedigree with oculocutaneous albinism by using targeted next-generation sequencing technology.

OBJECTIVE: To explore the genetic basis for a Chinese pedigree affected with split hand/foot malformation (SHFM). METHODS: Genomic DNA of the proband and other affected members was extracted from peripheral blood samples. Chromosomal microarray analysis was employed to detect genome-wide copy number variations (CNVs). RESULTS: A 400 kb microduplication was identified in the 10q24.31-q24.32 region among all affected individuals. The microduplication has involved four genes, namely LBX1, BTRC, POLL and DPCD, in addition with part of FBXW4 gene. CONCLUSION The 10q24.31-q24.32 microduplication has segregated with the disease phenotype in this pedigree and probably underlay the SHFM malformation in the patients.
Asian Continental Ancestry Group ; Chromosome Duplication ; Chromosomes, Human, Pair 10 ; genetics ; DNA Copy Number Variations ; Foot Deformities, Congenital ; genetics ; Genetic Testing ; Hand Deformities, Congenital ; genetics ; Humans ; Limb Deformities, Congenital ; genetics ; Pedigree

Objective:To assess the clinical value of quantitative fluorescent polymerase chain reaction(QF-PCR) in rapid prenatal diagnosis.Methods:From May 2018 to May 2019, 1 190 amniotic fluid samples were detected by QF-PCR to check out aneuploidies of 13, 18, 21, X and Y, then the results were compared with those of traditional karyotype analysis.Results:The 33 abnormities including 20 cases with trisomy 21, 4 cases with trisomy 18 and 9 abnormities of sex chromosomes were checked out in 1190 amniotic fluid samples by rapid diagnosis.Conclusion:As a common rapid diagnostic method, QF-PCR has advantages of rapid and accurate, but still cannot completely replace the conventional karyotype analysis.