1.Analysis of a patient with severe Hemophilia A due to a large duplication of F8 gene.
Wen WANG ; Dongyan CUI ; Lijuan JIANG ; Ai ZHANG ; Aiguo LIU ; Qun HU
Chinese Journal of Medical Genetics 2022;39(1):72-75
OBJECTIVE:
To report on a case with severe hemophilia A (HA) due to a large duplication of F8 gene.
METHODS:
Inversion detection, Sanger sequencing, and multiplex ligation-dependent probe amplification (MLPA) were used to detect the mutation in the proband and his mother.
RESULTS:
The patient, a 7-year-old boy, was diagnosed with severe HA at 8 months. No inhibitor was developed over 150 exposure days. Intronic inversion detection and Sanger sequencing have failed to identify pathogenic variants, while MLPA revealed a large duplication [Ex 1_22 dup (2 copies)] in the proband, for which his mother was a carrier [Ex 1_22 dup (3 copies)]. Large duplications of the F8 gene have so far been found in 24 HA patients, all of whom had a severe phenotype, only one had a history of inhibitors.
CONCLUSION
Large duplications of F8 gene are associated with severe HA. The diagnostic rate for HA may be increased by MLPA.
Child
;
Factor VIII/genetics*
;
Gene Duplication
;
Hemophilia A/genetics*
;
Humans
;
Introns
;
Male
;
Mutation
;
Phenotype
3.Clinical phenotype and genetic analysis of MECP2 duplication syndrome.
Duo CHEN ; Luxun WANG ; Yaqin HOU ; Panlai SHI ; Guijun QIN ; Xiangdong KONG
Chinese Journal of Medical Genetics 2021;38(12):1190-1193
OBJECTIVE:
To analyze the clinical symptom and parental origin of patients with MECP2 duplication syndrome in order to provide a basis for genetic counseling and prenatal diagnosis.
METHODS:
Clinical symptoms of four patients who were diagnosed with MECP2 duplication syndrome by copy number variation sequencing (CNV-Seq) were reviewed. The maternal origin of the duplications were verified.
RESULTS:
All patients were males, and CNV-Seq revealed that they have all harbored a duplication in the Xq28 region spanning 0.32 ~ 0.86 Mb, which were derived from asymptomatic mothers. The clinical symptoms of three patients with three copies included delayed speech, intellectual disability, and muscular hypotonia, while the patient with four copies had died at 6 months after birth, with clinical symptoms including recurrent infections, seizures, and spasticity.
CONCLUSION
The four cases of MECP2 duplication syndrome have shown complete penetrance and have all derived from asymptomatic mothers. As a stable and reliable method, CNV-Seq can accurately detect the MECP2 duplication syndrome.
Chromosomes, Human, X
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DNA Copy Number Variations
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Gene Duplication
;
Humans
;
Male
;
Mental Retardation, X-Linked
;
Methyl-CpG-Binding Protein 2/genetics*
;
Phenotype
5.Comprehensive genetic diagnosis of patients with Duchenne/Becker muscular dystrophy (DMD/BMD) and pathogenicity analysis of splice site variants in the DMD gene.
Yan-Mei YANG ; Kai YAN ; Bei LIU ; Min CHEN ; Li-Ya WANG ; Ying-Zhi HUANG ; Ye-Qing QIAN ; Yi-Xi SUN ; Hong-Ge LI ; Min-Yue DONG
Journal of Zhejiang University. Science. B 2019;20(9):753-765
Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are caused by mutations in the DMD gene. The aim of this study is to identify pathogenic DMD variants in probands and reduce the risk of recurrence of the disease in affected families. Variations in 100 unrelated DMD/BMD patients were detected by multiplex ligation-dependent probe amplification (MLPA) and next-generation sequencing (NGS). Pathogenic variants in DMD were successfully identified in all cases, and 11 of them were novel. The most common mutations were intragenic deletions (69%), with two hotspots located in the 5' end (exons 2-19) and the central of the DMD gene (exons 45-55), while point mutations were observed in 22% patients. Further, c.1149+1G>A and c.1150-2A>G were confirmed by hybrid minigene splicing assay (HMSA). This two splice site mutations would lead to two aberrant DMD isoforms which give rise to severely truncated protein. Therefore, the clinical use of MLPA, NGS, and HMSA is an effective strategy to identify variants. Importantly, eight embryos were terminated pregnancies according to prenatal diagnosis and a healthy boy was successfully delivered by preimplantation genetic diagnosis (PGD). Early and accurate genetic diagnosis is essential for prenatal diagnosis/PGD to reduce the risk of recurrence of DMD in affected families.
Alternative Splicing
;
Binding Sites
;
Biopsy
;
Creatine Kinase/blood*
;
Exons
;
Family Health
;
Female
;
Gene Deletion
;
Gene Duplication
;
Genetic Variation
;
Heterozygote
;
High-Throughput Nucleotide Sequencing
;
Humans
;
Male
;
Mothers
;
Muscular Dystrophy, Duchenne/genetics*
;
Phenotype
;
Polymorphism, Single Nucleotide
;
Pregnancy
6.Genetic analysis of a 46,XY female with sex reversal due to duplication of NR0B1 gene.
Shengfang QIN ; Xueyan WANG ; Yunxing LI
Chinese Journal of Medical Genetics 2018;35(6):804-807
OBJECTIVE:
To explore the pathogenesis of a 46,XY female with sex reversal.
METHODS:
Peripheral blood lymphocytes of the patient were subjected to G-banding karyotype analysis. Sex chromosomes were analyzed with fluorescence in situ hybridization (FISH). SRY gene was analyzed by Sanger sequencing. The whole exome of the patient was subjected to next generation sequencing. Copy number variations (CNVs) of the NR0B1, SF1, SRY, SOX9 and WNT4 genes were validated by multiplex ligation-dependent probe amplification (MLPA).
RESULTS:
The patient had a 46,XY karyotype. FISH analysis showed that her sex chromosomes were X and Y. No mutation was found in the SRY gene, and no pathogenic mutation was detected in her exome. However, a duplication spanning approximately 67.31 kb encompassing the MAGEB1, MAGEB3, MAGEB4 and NR0B1 genes at Xp21, was predicted by software analysis. MLPA confirmed duplication of the NR0B1 gene in the patient and her mother.
CONCLUSION
A duplication fragment of Xp21 encompassing the NR0B1 gene in the 46,XY female with sex reversal is transmitted from her asymptomatic carrier mother. Attention should be paid towards the insidious nature and high morbidity of this duplication.
DAX-1 Orphan Nuclear Receptor
;
genetics
;
DNA Copy Number Variations
;
Female
;
Gene Duplication
;
Genes, sry
;
Gonadal Dysgenesis, 46,XY
;
genetics
;
Humans
;
In Situ Hybridization, Fluorescence
7.Analysis of SCN1A deletions or duplications in patients with Dravet syndrome.
Qi ZENG ; Yuehua ZHANG ; Xiaoling YANG ; Xiaojing XU ; Jing ZHANG ; Xiaojuan TIAN ; Aijie LIU ; Xiaoyan LIU ; Yuwu JIANG ; Xiru WU
Chinese Journal of Medical Genetics 2017;34(6):787-791
OBJECTIVETo determine the type and frequency of SCN1A deletions and duplications among patients with Dravet syndrome (DS).
METHODSFor DS patients in which no mutations of the SCN1A gene were detected by PCR-DNA sequencing, SCN1A deletions and duplications were detected by multiplex ligation-dependent probe amplification (MLPA).
RESULTSIn 680 DS patients, 489 had SCN1A mutations identified by PCR-DNA sequencing. In 191 patients who were negative for the SCN1A PCR-DNA sequencing, 15 (15/191, 7.9%) were detected with heterozygous SCN1A deletions or duplications, which included 14 (14/15, 93.3%) SCN1A deletions and 1 SCN1A duplication. There were 13 types of mutations, including whole SCN1A deletions in 3 patients, partial SCN1A deletions in 11 patients and partial SCN1A duplications in one patient. By testing the parents, 14 mutations were found to be de novo. For the remaining case, no SCN1A deletion or duplication was found in the mother, while the father was not available.
CONCLUSIONApproximately 8% of Chinese patients who were negative for SCN1A mutation by PCR-sequencing have SCN1A deletions or duplications. The MLPA analysis should be considered as an important strategy for such patients. SCN1A deletions are more common than SCN1A duplications among DS patients, and the most common types are whole SCN1A deletions. The majority of SCN1A deletions or duplications are de novo.
Epilepsies, Myoclonic ; genetics ; Female ; Gene Deletion ; Gene Duplication ; Humans ; Infant ; Male ; Multiplex Polymerase Chain Reaction ; NAV1.1 Voltage-Gated Sodium Channel ; genetics
8.Evolutionary and Comparative Genomics to Drive Rational Drug Design, with Particular Focus on Neuropeptide Seven-Transmembrane Receptors.
Michael FURLONG ; Jae Young SEONG
Biomolecules & Therapeutics 2017;25(1):57-68
Seven transmembrane receptors (7TMRs), also known as G protein-coupled receptors, are popular targets of drug development, particularly 7TMR systems that are activated by peptide ligands. Although many pharmaceutical drugs have been discovered via conventional bulk analysis techniques the increasing availability of structural and evolutionary data are facilitating change to rational, targeted drug design. This article discusses the appeal of neuropeptide-7TMR systems as drug targets and provides an overview of concepts in the evolution of vertebrate genomes and gene families. Subsequently, methods that use evolutionary concepts and comparative analysis techniques to aid in gene discovery, gene function identification, and novel drug design are provided along with case study examples.
Drug Design*
;
Gene Duplication
;
Genetic Association Studies
;
Genome
;
Genomics*
;
Humans
;
Ligands
;
Neuropeptides*
;
Vertebrates
9.Detection of a fetus with paternally derived 2q37.3 microdeletion and 20p13p12.2 microduplication using whole genome microarray technology.
Lin ZHANG ; Meihong REN ; Guining SONG ; Xuexia LIU ; Jianliu WANG ; Xiaohong ZHANG
Chinese Journal of Medical Genetics 2016;33(6):820-823
OBJECTIVETo perform prenatal diagnosis for a fetus with multiple malformations.
METHODSThe fetus was subjected to routine karyotyping and whole genome microarray analysis. The parents were subjected to high-resolution chromosome analysis.
RESULTSFetal ultrasound at 28+4 weeks has indicated intrauterine growth restriction, left kidney agenesis, right kidney dysplasia, ventricular septal defect, and polyhydramnios. Chromosomal analysis showed that the fetus has a karyotype of 46,XY,der(2),der(20), t(2;20)(q37.3;p12.2), t(5;15) (q12.2;q25) pat. SNP array analysis confirmed that the fetus has a 5.283 Mb deletion at 2q37.3 and a 11.641 Mb duplication at 20p13p12.2. High-resolution chromosome analysis suggested that the father has a karyotype of 46,XY,t(2;20)(q37.3;p12.2),t(5;15)(q12.2;q25), while the mother has a normal karyotype.
CONCLUSIONThe abnormal phenotype of the fetus may be attributed to a 2q37.3 microdeletion and a 20p13p12.2 microduplication. The father has carried a complex translocation involving four chromosomes. To increase the chance for successful pregnancy, genetic diagnosis and/or assisted reproductive technology are warranted.
Abnormalities, Multiple ; genetics ; Adult ; Chromosome Deletion ; Chromosomes ; genetics ; Female ; Fetus ; abnormalities ; Gene Duplication ; genetics ; Humans ; Karyotyping ; methods ; Male ; Pregnancy ; Prenatal Diagnosis ; methods
10.Mutation analysis of 81 cases with Duchenne/Becker muscular dystrophy.
Shuang LI ; Ying BAI ; Zhenhua ZHAO ; Xiangdong KONG
Chinese Journal of Medical Genetics 2016;33(6):762-767
OBJECTIVETo perform mutation analysis for 81 unrelated patients with Duchenne/Becker muscular dystrophy (DMD/BMD) from Henan Province.
METHODSMultiplex ligation-dependent probe amplification (MLPA) was used to detect potential deletion/duplications of the DMD gene. Those with single exon deletions were validated with PCR amplification and Sanger sequencing to rule out false positive results. Patients with negative MLPA results were further analyzed with next-generation sequencing (NGS), and the result was validated by Sanger sequencing.
RESULTSDMD gene deletion/duplications were detected in 67 cases by MLPA, and exons 45-54 was the most frequently deleted. The phenotypes of 79.1% patients with a deletion or duplication has conformed to the reading frame rule. In addition, 13 mutations were detected by NGS and Sanger sequencing, which included 6 novel mutations including one frameshift mutation c.4708-4709insTG and 5 nonsense mutations (c.8812G>T, c.2131A>T, c.6035T>A, c.3426C>A, and c.3055C>T).
CONCLUSIONThis results have enriched the DMD gene mutation database. Combined MLPA, NGS and Sanger sequencing can greatly enhance the sensibility and specificity of genetic testing for the DMD/BMD.
Adolescent ; Adult ; Child ; Child, Preschool ; DNA Mutational Analysis ; methods ; Female ; Gene Deletion ; Gene Duplication ; genetics ; Humans ; Infant ; Male ; Middle Aged ; Muscular Dystrophy, Duchenne ; genetics ; Mutation ; genetics ; Young Adult

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