ABSTRACT
<p><b>OBJECTIVE</b>To assess the value of G-banded karyotyping in combination with multiplex ligation-dependent probe amplification (MLPA) as a tool for the detection of chromosomal abnormalities in fetuses with congenital heart defects.</p><p><b>METHODS</b>The combined method was used to analyze 104 fetuses with heart malformations identified by ultrasonography. Abnormal findings were confirmed with chromosomal microarray analysis (CMA).</p><p><b>RESULTS</b>Nineteen (18%) fetuses were found to harbor chromosomal aberrations by G-banded karyotyping and MLPA. For 93 cases, CMA has detected abnormalities in 14 cases including 10 pathogenic copy number variations (CNVs) and 4 CNVs of uncertain significance (VOUS). MLPA was able to detect all of the pathogenic CNVs and 1 VOUS CNV.</p><p><b>CONCLUSION</b>Combined use of G-banded karyotyping and MLPA is a rapid, low-cost and effective method to detect chromosomal abnormalities in fetuses with various heart malformations.</p>
Subject(s)
Female , Humans , Pregnancy , Chromosome Aberrations , Chromosome Banding , Chromosome Disorders , Diagnosis , Genetics , DNA Copy Number Variations , Fetal Diseases , Diagnosis , Genetics , Genetic Testing , Methods , Heart Defects, Congenital , Diagnosis , Genetics , Karyotyping , Methods , Multiplex Polymerase Chain Reaction , Methods , Prenatal Diagnosis , Methods , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
<p><b>OBJECTIVE</b>To identify potential mutation of SLC22A5 gene in a 5-month-old boy affected with primary carnitine deficiency and provide genetic counseling and prenatal diagnosis for the members of his family.</p><p><b>METHODS</b>DNA was extracted from peripheral blood samples derived from the proband, his parents and elder sister, as well as amniotic fluid from his pregnant mother. All of the 10 exons of the SLC22A5 gene were amplified by PCR and subjected to Sanger sequencing. The amniotic fluid sample was also subjected to G-banded karyotyping and multiplex ligation-dependent probe amplification (MLPA).</p><p><b>RESULTS</b>A homozygous mutation c.760C>T (p.R254X) of the SLC22A5 gene was detected in the proband. Heterozygous mutation c.760C>T (p.R254X) was also found in other family members including the fetus. The karyotyping and chromosomal microdeletion testing for the amniotic fluid sample were both normal.</p><p><b>CONCLUSION</b>The newly identified homozygous nonsense c.760C>T (p.R254X) mutation of the SLC22A5 gene probably underlies the primary carnitine deficiency of the proband. Genetic counseling and prenatal diagnosis have been provided for this family.</p>
Subject(s)
Adult , Female , Humans , Infant , Male , Pregnancy , Asian People , Genetics , Base Sequence , Cardiomyopathies , Embryology , Genetics , Carnitine , Genetics , China , Exons , Genotype , Hyperammonemia , Embryology , Genetics , Molecular Sequence Data , Muscular Diseases , Embryology , Genetics , Organic Cation Transport Proteins , Genetics , Pedigree , Prenatal Diagnosis , Solute Carrier Family 22 Member 5ABSTRACT
<p><b>OBJECTIVE</b>To identify potential mutations among three sisters from a Chinese family suspected with Cockayne syndrome for growth and psychomotor retardation, and to offer genetic counseling and prenatal diagnosis for the family.</p><p><b>METHODS</b>G-banded karyotyping, microarray comparative genomic hybridization (CM-CGH), whole genome exon high-throughput sequencing and Sanger sequencing were employed to identify potential genetic variations for the three patients and their parents.</p><p><b>RESULTS</b>Whole exome sequencing has identified two novel missense mutations, i.e., c.1595A>G (p.Asp532Gly) and c.1607T>G (p.Leu536Trp), in exon 7 of excision repair cross-complementing rodent repair deficiency, complementation group 6 (ERCC6) gene. Sanger sequencing confirmed that all of the three sisters have inherited one of the mutations (c.1607T>G) from their father and another (c.1595A>G) from their mother.</p><p><b>CONCLUSION</b>Three sisters have all been identified as double heterozygote for mutations c.1607T>G and c.1595A>G and were diagnosed with Cockayne syndrome.</p>
Subject(s)
Adult , Child, Preschool , Female , Humans , Infant , Male , Asian People , Genetics , Base Sequence , Cockayne Syndrome , Diagnosis , Genetics , DNA Helicases , Genetics , DNA Repair Enzymes , Genetics , Exons , Heterozygote , Molecular Sequence Data , Pedigree , Point Mutation , Poly-ADP-Ribose Binding ProteinsABSTRACT
<p><b>OBJECTIVE</b>To use array comparative genomic hybridization (array-CGH) and multiplex ligation-dependent probe amplification (MLPA) to detect unbalanced rearrangements in 4 cases suspected to have chromosome disease but were undetected with conventional karyotype analysis, and to assess the applicability of array-CGH and MLPA for detection of unbalanced translocation.</p><p><b>METHODS</b>Genomic DNA was extracted with standard procedures. All cases were analyzed by array-CGH and subtelomeric MLPA.</p><p><b>RESULTS</b>All of the cases were identified to have unbalanced translocations by array-CGH analysis, among which 3 were consistent with subtelomeric MLPA analysis. For the remaining one, its chromosomal abnormality was not detected by MLPA as the imbalance has occurred outside of target regions.</p><p><b>CONCLUSION</b>Both array-CGH and MLPA techniques can complement conventional karyotyping for detecting unbalanced translocations. The combination features both high resolution and efficiency for clinical use.</p>
Subject(s)
Adult , Child , Humans , Infant , Male , Chromosome Deletion , Chromosome Duplication , Comparative Genomic Hybridization , Karyotyping , Multiplex Polymerase Chain Reaction , Phenotype , Translocation, GeneticABSTRACT
<p><b>OBJECTIVE</b>To perform mutation analysis for a female with multiple epiphyseal dysplasia (MED) and provide pre-symptomatic and prenatal diagnosis.</p><p><b>METHODS</b>Mutation screening of cartilage oligomeric matrix protein (COMP) gene was carried out through targeted next-generation DNA sequencing and Sanger sequencing.</p><p><b>RESULTS</b>A novel c.956 A>T resulting in substitution of Aspartic acid 319 for Valine (p.Asp319Val) has been identified in exon 9 of the COMP gene in the patient. As predicted by a SIFT software, above mutation can cause damage to the structure of COMP protein.</p><p><b>CONCLUSION</b>A novel c.956 A>T substitution mutation has been identified in a patient featuring MED.</p>
Subject(s)
Adult , Female , Humans , Base Sequence , Cartilage Oligomeric Matrix Protein , Exons , Extracellular Matrix Proteins , Genetics , Glycoproteins , Genetics , Matrilin Proteins , Mutation , Osteochondrodysplasias , Diagnosis , Genetics , Polymorphism, Single Nucleotide , Sequence AlignmentABSTRACT
Objective To estimate clinical application of multiplex ligation-dependent probe amplification (MLPA) for rapid prenatal detection of aneuploid abnormalities in amniotic fluid.Methods Totally 1229 amniotic fluid samples were collected from the pregnant women receving prenatal diagnosis for chromosomal abnormalities in Prenatal Diagnosis Center of Shenzhen Maternity and Child Healthcare Hospital from October 2009 to December 2010.All the samples were investigated independently with both MLPA and G-band karyotyping to detect aneuploidies of chromosomes X,Y,13,18 and 21.A comparison was followed the results acquired from two methods for evaluation of sensitivity and specificity of MLPA.ResultsThirtyeight aneuploidies were detected by G-band karyotyping,in which 34 were nonmosaic aneuploidies and 4were mosaic aneuploidies.MLPA and G-band karyotyping had consistent results in detecting the nonmosaic aneuploidies of chromosomes X,Y,13,18 and 21. Among 4 mosaic aneuploidies detected by G-band karyotyping,2 were confirmed by MLPA independently.Conclusions The sensitivity and specificity of MLPA in detecting the nonmosaic aneuploidies of chromosomes X,Y,13,18 and 21 were clinically acceptable.MLPA provides an efficient,reliable method for rapid detection of aneuploidies.
ABSTRACT
<p><b>OBJECTIVE</b>To study the mutation of the androgen receptor gene in a family with complete androgen insensitivity syndrome and to explore the pathogenicity of the mutation.</p><p><b>METHODS</b>PCR and DNA sequencing were performed to study the AR gene mutation; Mbo I restriction endonuclease was used to detect existence of the mutation in normal controls; conservation of the mutation site was analyzed by comparison of the sequence of amino acid among different species.</p><p><b>RESULTS</b>The DNA sequence of the three patients contained the same substitution of a single nucleotide on codon 681 GAG to GAT of exon 4, which located in the ligand binding domain of the AR receptor and led to substitution of glutamic acid to aspartic acid in the AR receptor. Their mother was heterozygote of E681D. E681D was not observed in the normal controls. The E681 site was extremely conservative in different species.</p><p><b>CONCLUSION</b>The E681D mutation of the AR gene is a novel mutation of leading to complete androgen insensitivity syndrome.</p>
Subject(s)
Adult , Animals , Female , Humans , Male , Middle Aged , Young Adult , Amino Acid Sequence , Androgen-Insensitivity Syndrome , Genetics , Base Sequence , DNA Mutational Analysis , Molecular Sequence Data , Mutation , Pedigree , Receptors, Androgen , Chemistry , Genetics , Sequence AlignmentABSTRACT
Objective To evaluate the clinical value of multiplex ligation-dependent probe amplification (MLPA) technique used in karyotype analysis of chorionic villi from missed abortion. Methods Feb 2008 to Oct 2008, 91 patients with missed abortion diagnosed by hormonal measurement, type B ultrasound and physical exam matched with 20 normal pregnant women undergoing artificial abortion were enrolled in this study. Chorionic villi was obtained by suction dilation and curettage in aseptic condition, then those villi was cultured and analyzed by traditional cytogenetic karyotyping method, in the mean time, the DNA extracted from villi was detected by MLPA. The results of chromosomal G-banding of chorionic villi were compared between two methods. Results The diagnostic concordance of MLPA and traditional karyotyping was observed in 92% (84/91) cases, there were 84 cases in the case group with diagnostic concordance by traditional karyotyping and MLPA except 7 cases of euploidy could not be detected by MLPA. The 84 cases included 40 normal karyotype,29 trisomy of euchromosome, 1 double trisomy of euchromosome, 10 monosomy X , 1 monosomy X combined with trisomy of euchromosome, 2 chimaera of X chromosome, 1 structural abnormity of euchromosome. Among 7 cases with discordance diagnosis, 2 cases with trisomy and 5 cases with tetrasomy of euchromosome were identified in traditional karyotyping, however, they were all diagnosed with normal disomy by MLPA. Of 20 villi from normal pregnancy, two methods got the consistent results. Conclusion The MLPA was rapid and efficacy method used for analyzing aneuploids in chorionic villi.
ABSTRACT
<p><b>OBJECTIVE</b>To analyze the chromosome aberration in a full-term male neonate with low birth weight, and to explore the possible causes for growth retardation in intrauterine development for the neonate.</p><p><b>METHODS</b>Genomic DNA was extracted from peripheral leukocytes of the neonate. Detection of genomic DNA copy number gain and loss was performed using microarray comparative genomic hybridization. Chromosome karyotype was obtained from cultured lymphocytes for the neonate and his parents in order to identify the origin of chromosome aberration.</p><p><b>RESULTS</b>Gain of 10q25.2-->qter (22 Mb) was observed in the full-term neonate with low birth weight. In addition, one chromosomal region, 15q26.2-->qter (5 Mb) was lost. The karyotype of the neonate was 46, XY, -15, +der(15), t(10;15)(q25;q26)pat.</p><p><b>CONCLUSION</b>The full-term neonate with low birth weight had a partial trisomy of 10q25.2-->qter with a partial monosomy of 15q26.2-->qter, both of them may contribute to the growth retardation in intrauterine development for the neonate case.</p>