OBJECTIVE: To explore the genetic basis for 7 families with gonadal mosaicism for Duchenne muscular dystrophy (DMD). METHODS: For the 7 families presented at the CITIC Xiangya Reproductive and Genetic Hospital from September 2014 to March 2022, clinical data were collected. Preimplantation genetic testing for monogenic disorders (PGT-M) was carried out for the mother of the proband from family 6. Peripheral venous blood samples of the probands, their mothers and other patients from the families, amniotic fluid samples from families 1 ~ 4 and biopsied cells of embryos cultured in vitro from family 6 were collected for the extraction of genomic DNA. Multiplex ligation-dependent probe amplification (MLPA) was carried out for the DMD gene, and short tandem repeat (STR)/single nucleotide polymorphism (SNP)-based haplotypes were constructed for the probands, other patients, fetuses and embryos. RESULTS: The results of MLPA showed that the probands and the fetuses/probands' brothers in families 1 ~ 4, 5, 7 had carried the same DMD gene variants, whilst the probands' mothers were all normal. The proband in family 6 carried the same DMD gene variant with only 1 embryo (9 in total) cultured in vitro, and the DMD gene of the proband's mother and the fetus obtained through the PGT-M were normal. STR-based haplotype analysis showed that the probands and the fetuses/probands' brothers in families 1 ~ 3 and 5 have inherited the same maternal X chromosome. SNP-based haplotype analysis showed that the proband from family 6 has inherited the same maternal X chromosome with only 1 embryo (9 in total) cultured in vitro. The fetuses in families 1 and 6 (via PGT-M) were both confirmed to be healthy by follow up, whilst the mothers from families 2 and 3 had chosen induced labor. CONCLUSION Haplotype analysis based on STR/SNP is an effective method for judging gonad mosaicism. Gonad mosaicisms should be suspected for women who have given births to children with DMD gene variants but with a normal peripheral blood genotype. Prenatal diagnosis and reproductive intervention may be adapted to reduce the births of further affected children in such families.
Male ; Pregnancy ; Child ; Humans ; Female ; Muscular Dystrophy, Duchenne/diagnosis* ; Dystrophin/genetics* ; Mosaicism ; Exons ; Prenatal Diagnosis/methods* ; Nucleotides

OBJECTIVE: To analyze a child with 11β hydroxylase deficiency (11β-OHD) due to CYP11B2/CYP11B1 chimeric gene. METHODS: Clinical data of the child who was admitted to Henan Children's Hospital on August 24, 2020 were retrospectively analyzed. Peripheral blood samples of the child and his parents were collected and subjected to whole exome sequencing (WES). Candidate variant was verified by Sanger sequencing. RT-PCR and Long-PCR were carried out to verify the presence of chimeric gene. RESULTS: The patient, a 5-year-old male, had featured premature development of secondary sex characteristics and accelerated growth, and was diagnosed with 21 hydroxylase deficiency (21-OHD). WES revealed that he has harbored a heterozygous c.1385T>C (p.L462P) variant of the CYP11B1 gene, in addition to a 37.02 kb deletion on 8q24.3. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the c.1385T>C (p.L462P) was rated as a likely pathogenic variant (PM2_Supporting+PP3_Moderate+PM3+PP4). The results of RT-PCR and Long-PCR suggested that CYP11B1 and CYP11B2 genes have recombined to form a CYP11B2 exon 1~7/CYP11B1 exon 7~9 chimeric gene. The patient was diagnosed as 11β-OHD and effectively treated with hydrocortisone and triptorelin. A healthy fetus was delivered following genetic counseling and prenatal diagnosis. CONCLUSION 11β-OHD may be misdiagnosed as 21-OHD due to the potential CYP11B2/CYP11B1 chimeric gene, which will require multiple methods for the detection.
Child, Preschool ; Humans ; Male ; Adrenal Hyperplasia, Congenital/genetics* ; Cytochrome P-450 CYP11B2/genetics* ; Exons ; Retrospective Studies ; Steroid 11-beta-Hydroxylase/genetics*

OBJECTIVE: To explore the clinical characteristics and genetic etiology of three children with Menkes disease. METHODS: Three children who had presented at the Children's Medical Center, the Affiliated Hospital of Guangdong Medical University from January 2020 to July 2022 were selected as the study subjects. Clinical data of the children were reviewed. Genomic DNA was extracted from peripheral blood samples of the children, their parents and sister of child 1. Whole exome sequencing (WES) was carried out. Candidate variants were verified by Sanger sequencing, copy number variation sequencing (CNV-seq), and bioinformatic analysis. RESULTS: Child 1 was a 1-year-and-4-month male, and children 2 and 3 were monozygotic twin males aged 1-year-and-10-month. The clinical manifestations of the three children have included developmental delay and seizures. WES showed that child 1 has harbored a c.3294+1G>A variant of the ATP7A gene. Sanger sequencing confirmed that his parents and sister did not carry the same variant, suggesting that it was de novo. Children 2 and 3 had carried a c.77266650_77267178del copy number variation. CNV-seq results showed that their mother has carried the same variant. By searching the HGMD, OMIM and ClinVar databases, the c.3294+1G>A was known to be pathogenic. No carrier frequency has been recorded in the 1000 Genomes, ESP, ExAC and gnomAD databases. Based on the Standards and Guidelines for the Interpretation of Sequence Variants: A Joint Consensus Recommendation of the American College of Medical Genetics and Genomics (ACMG), the ATP7A gene c.3294+1G>A variant was predicted to be pathogenic. The c.77266650_77267178del variant has involved exons 8 to 9 of the ATP7A gene. ClinGen online system score for it was 1.8, which was also considered to be pathogenic. CONCLUSION The c.3294+1G>A and c.77266650_ 77267178del variants of the ATP7A gene probably underlay the Menkes disease in the three children. Above finding has enriched the mutational spectrum of Menkes disease and provided a basis for clinical diagnosis and genetic counseling.
Humans ; Male ; Computational Biology ; Copper-Transporting ATPases/genetics* ; DNA Copy Number Variations ; Exons ; Menkes Kinky Hair Syndrome/genetics* ; Mutation ; Peptide Fragments ; Seizures ; Infant

OBJECTIVE: To explore the genetic basis for four patients suspected for Marfan syndrome (MFS). METHODS: Four male patients with suspected MFS and their family members who were treated at West China Second Hospital of Sichuan University from September 12, 2019 to March 27, 2021 were selected as the study subjects. Peripheral venous blood samples were collected from the patients and their parents or other pedigree members for the extraction of genomic DNA. Whole exome sequencing was carried out, and candidate variants were validated by Sanger sequencing. The pathogenicity of the variants was determined based on the guidelines from the American College of Medical Genetics and Genomics (ACMG). RESULTS: Genetic testing revealed that all four patients have harbored variants of the FBN1 gene, including c.430_433del (p.His144fs) deletional variant in exon 5, c.493C>T (p.Arg165*) nonsense variant in exon 6, c.5304_5306del (p.Asp1768del) deletional variant in exon 44 and c.5165C>G (p.Ser1722Cys) missense variant in exon 42. According to the ACMG guidelines, the c.430_433del and c.493C>T were classified as pathogenic variants (PVS1+PM2_Supporting+PP4; PVS1+PS1+PS2+PM2_Supporting+PP4). c.5304_5306del and c.5165C>G were classified as likely pathogenic variants (PS2+PM2_Supporting+PM4+PP4; PS2_Moderate+PS1+PM1+PM2_Supporting). CONCLUSION The c.430_433del and c.5304_5306del variants of the FBN1 gene identified in this study were unreported previously. Above results have enriched the variation spectrum of the FBN1 gene and provided a basis for genetic counseling and prenatal diagnosis of patients with MFS and acromicric dysplasia.
Female ; Pregnancy ; Humans ; Male ; Exons ; China ; Family ; Genetic Counseling ; Genetic Testing ; Marfan Syndrome/genetics* ; Mutation ; Fibrillin-1/genetics*

OBJECTIVE: To explore the genetic etiology for a child with profound intellectual disabilities and obvious behavioral abnormalities. METHODS: A male child who had presented at the Zhongnan Hospital of Wuhan University on December 2, 2020 was selected as the study subject. Peripheral blood samples of the child and his parents were collected and subjected to whole exome sequencing (WES). Candidate variant was verified by Sanger sequencing. Short tandem repeat (STR) analysis was carried out to determine its parental origin. The splicing variant was also validated in vitro with a minigene assay. RESULTS: WES results revealed that the child had harbored a novel splicing variant of c.176-2A>G in the PAK3 gene, which was inherited from his mother. The results of minigene assay have confirmed aberrant splicing of exon 2. According to the guidelines from the American College of Medical Genetics and Genomics, it was classified as a pathogenic variant (PVS1+PM2_Supporting+PP3). CONCLUSION The novel splicing variant c.176-2A>G of the PAK3 gene probably underlay the disorder in this child. Above finding has expanded the variation spectrum of the PAK3 gene and provided a basis for genetic counseling and prenatal diagnosis for this family.
Child ; Female ; Humans ; Male ; Pregnancy ; Exons ; Intellectual Disability/genetics* ; Mothers ; Mutation ; p21-Activated Kinases/genetics* ; Parents ; RNA Splicing

OBJECTIVE: To analyze the RHD genotype of a blood donor with Del phenotype in Yunnan. METHODS: Rh serological phenotype was identified. RHD gene was detected by PCR-SSP typing, and its 10 exons were sequenced. Exon 9 was amplified for sequencing and analysis. RHD zygosity was detected. RESULTS: The Rh phenotype of this specimen was CcD^elee. Genomic DNA exhibited a 1 003 bp deletion spanning from intron 8, across exon 9 into intron 9. The deletion breakpoints occurred between two 7-bp short tandem repeat sequences. There was no variation in the sequences of the remaining exons. The Rh hybridization box test showed that there was one RHD negative allele. CONCLUSION This specimen is Del type caused by deletion of RHD exon 9.
Humans ; Blood Donors ; Rh-Hr Blood-Group System/genetics* ; China ; Phenotype ; Exons ; Genotype ; Alleles

With the development of precision diagnosis and treatment for non-small cell lung cancer (NSCLC), the epidermal growth factor receptor (EGFR) exon 20 insertion (ex20ins) mutations, as a rare subset of EGFR mutaions, have gradually attracted attention recently. The heterogeneity of EGFR ex20ins mutations is very high, different variants have different clinical benefits, and the prognosis is extremely poor. The available traditional treatment outcomes are poor in patients with EGFR ex20ins positive NSCLC and polymerase chain reaction (PCR) tests would miss aprocimately 50% of the variants. Therefore, high attention should be paid to EGFR ex20ins positive NSCLC during the clinical practice. The expert panel has formed a consensus on the standardized clinical diagnosis and treatment of EGFR ex20ins mutation NSCLC through reference to literature and clinical data, and combined with the experts' own clinical experience, the consensus recommendations including clinicopathologic characteristics, therapies, testing methods and recent relevant clinical trials for NSCLC patients with EGFR ex20ins mutation, in order to provide medication reference for clinical physicians at all levels.
Humans ; Carcinoma, Non-Small-Cell Lung/therapy* ; Consensus ; ErbB Receptors/genetics* ; Exons ; Lung Neoplasms/therapy* ; Mutagenesis, Insertional

The mesenchymal-epithelial transition factor (MET) exon 14 skipping mutation is mainly caused by the loss of c-Cbl tyrosine binding site. This mutation could result in a decrease in the degradation rate of proteasome-mediated MET proteins, trigger continuous activation of downstream pathways, and ultimately lead to tumorigenesis. The incidence of MET exon 14 skipping mutation in patients with non-small cell lung cancer (NSCLC) is 0.9% to 4.0%. Patients with advanced NSCLC are recommended to test MET exon 14 skipping mutations who may benefit from MET inhibitors-targeted therapy. MET inhibitors have a high objective response rate and good safety profiles, which could prolong the survival of NSCLC patients with MET exon 14 skipping mutations. The Lung Cancer Specialty Committee of Chinese Elderly Health Care Association organized multidisciplinary experts to give suggestions on the important issues of clinical aspects for targeted therapy of MET exon 14 skipping mutation in NSCLC according to the clinical practice experiences and evidences based medicine. "Expert Consensus on Targeted Therapy of NSCLC with MET Exon 14 Skipping Mutation" is proposed, aiming to provide standardized guidances for the clinical practice of Chinese physicians.
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Humans ; Aged ; Carcinoma, Non-Small-Cell Lung/genetics* ; Lung Neoplasms/genetics* ; Consensus ; Proto-Oncogene Proteins c-met/genetics* ; Mutation ; Exons ; Protein Kinase Inhibitors/therapeutic use*

Objective: Glycogen storage disease type IX (GSD-IX) is a rare primary glucose metabolism abnormality caused by phosphorylase kinase deficiency and a series of pathogenic gene mutations. The clinical characteristics, gene analysis, and functional verification of a mutation in a child with hepatomegaly are summarized here to clarify the pathogenic cause of the disease. Methods: The clinical data of a child with GSD-IX was collected. Peripheral blood from the child and his parents was collected for genomic DNA extraction. The patient's gene diagnosis was performed by second-generation sequencing. The suspected mutations were verified by Sanger sequencing and bioinformatics analysis. The suspected splicing mutations were verified in vivo by RT-PCR and first-generation sequencing. Results: Hepatomegaly, transaminitis, and hypertriglyceridemia were present in children. Liver biopsy pathological examination results indicated glycogen storage disease. Gene sequencing revealed that the child had a c.285 + 2_285 + 5delTAGG hemizygous mutation in the PHKA2 gene. Sanger sequencing verification showed that the mother of the child was heterozygous and the father of the child was of the wild type. Software such as HSF3.1 and ESEfinder predicted that the gene mutation affected splicing. RT-PCR of peripheral blood from children and his mother confirmed that the mutation had caused the skipping of exon 3 during the constitutive splicing of the PHKA2 gene. Conclusion: The hemizygous mutation in the PHKA2 gene (c.285 + 2_285 + 5delTAGG) is the pathogenic cause of the patient's disease. The detection of the novel mutation site enriches the mutation spectrum of the PHKA2 gene and serves as a basis for the family's genetic counseling.
Child ; Humans ; Exons ; Glycogen Storage Disease/genetics* ; Hepatomegaly/genetics* ; Mutation ; Phosphorylase Kinase/genetics* ; Male ; Female

OBJECTIVE: To explore the molecular mechanism for an individual with Bweak subtype. METHODS: Serological methods were used to identify the proband's phenotype. In vitro enzyme activity test was used to determine the activity of B-glycosyltransferase (GTB) in her serum. The genotype was determined by PCR amplification and direct sequencing of exons 5 to 7 and flanking sequences of the ABO gene. T-A cloning technology was used to isolate the haploids. The primary physical and chemical properties and secondary structure of the protein were analyzed with the ProtParam and PSIPRED software. Three software, including PolyPhen-2, SIFT, and PROVEAN, was used to analyze the effect of missense variant on the protein. RESULTS: Serological results showed that the proband's phenotype was Bweak subtype with anti-B antibodies presented in her serum. In vitro enzyme activity assay showed that the GTB activity of the subject was significantly reduced. Analysis of the haploid sequence revealed a c.398T>C missense variant on the B allele, which resulted in a novel B allele. The 398T>C variant has caused a p.Phe133S substitution at position 133 of the GTB protein. Based on bioinformatic analysis, the amino acid substitution had no obvious effect on the primary and secondary structure of the protein, but the thermodynamic energy of the variant protein has increased to 6.07 kcal/mol, which can severely reduce the protein stability. Meanwhile, bioinformatic analysis also predicted that the missense variant was harmful to the protein function. CONCLUSION The weak expression of the Bweak subtype may be attributed to the novel allele of ABO*B.01-398C. Bioinformatic analysis is helpful for predicting the changes in protein structure and function.
Female ; Animals ; ABO Blood-Group System/genetics* ; Phenotype ; Genotype ; Exons ; Alleles