Dystrophinopathies, including Duchenne muscular dystrophy, Becker muscular dystrophy and dilated cardiomyopathy, are X-linked recessive genetic disorders due to variants of the dystrophin gene, which can seriously affect quality of life and health. Genetic diagnosis plays a crucial role in their diagnosis, treatment, and prevention. How to rationally select and standardize the use of various genetic techniques is a skill that clinicians must acquire. By compiling expertise of experts from the relevant areas and guidelines published home and abroad, this consensus has provided a guidance from the perspective of genetic diagnosis for the selection of genetic techniques, testing strategies, and detection process for dystrophinopathies.
Humans ; Quality of Life ; Consensus ; Dystrophin/genetics* ; Muscular Dystrophy, Duchenne/therapy* ; Cardiomyopathy, Dilated/genetics* ; Electrocardiography

OBJECTIVE: To investigate the clinical phenotype and genetic characteristics of a Chinese pedigree affected with Cohen syndrome. METHODS: A proband who was admitted to Zhengzhou People's Hospital on June 2, 2021 due to intellectual disability and developmental delay, in addition with her younger sister and other family members, were selected as the study subjects. Clinical data of the proband and her younger sister were collected. Genomic DNA was extracted from peripheral venous blood and chorionic villi samples. Chromosomal abnormalities were detected with chromosomal microarray analysis (CMA). Whole exome sequencing (WES) and Sanger sequencing were carried out to detect candidate variants in the proband. With RNA extracted from the peripheral blood samples, VPS13B gene transcripts and expression were analyzed by PCR and real-time quantitative PCR. Prenatal diagnosis was carried out at 12 weeks' gestation. RESULTS: The proband was a 10-year-old female with clinical manifestations including development delay, obesity, severe myopia and peculiar facial features. Her sister was 3 years old with a similar phenotype. CMA revealed no chromosomal abnormality in the proband, while WES results revealed that the proband and her sister had both harbored compound heterozygous variants of the VPS13B gene, namely c.10076_10077delCA (p.T3359fs*29) and c.6940+1G>T, which were respectively inherited from their mother and father. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), both variants were classified as pathogenic (PVS1+PS4+PM4+PP1; PVS1+PM2_Supporting+PM3+PP1). In vivo splicing assay confirmed that the c.6940+1G>T variant has produced a frameshift transcript with skipping of exon 38. Compared with the control group, the expression of RNA in the peripheral blood of the proband's parents has decreased to 65% ~ 70% (P < 0.01), whilst that in the proband and her sister has decreased to 40% (P < 0.001). Prenatal diagnosis at 12 weeks of gestation has found that the fetus only harbored the heterozygous c.10076_ 10077delCA variant. CONCLUSION The c.10076_10077delCA (p.T3359fs*29) frameshift variant and c.6940+1G>T splicing variant probably underlay the Cohen syndrome in this pedigree. Genetic testing has facilitated the diagnosis of this disease.
Female ; Humans ; East Asian People ; Intellectual Disability/genetics* ; Mutation ; Myopia/genetics* ; Pedigree ; Vesicular Transport Proteins/genetics* ; Child, Preschool ; Child

Objective:To provide experimental evidence for genetic counseling and prenatal diagnosis by analyzing the clinical characteristics, screening and identification of the function of suspicious variants in a X-1inked spondyloepiphyseal dysplasia tarda (SEDT) family.Methods:The family members' medical history, general physical examination, femur, spine X-ray examination were collected. Peripheral blood samples of the family members were collected and DNA was extracted from these samples. Sequencing clinical whole exons of proband DNA by targeted gene high-throughput sequencing method, then analysis sequencing data. The suspicious mutation was confirmed in pedigree members by PCR and Sanger sequencing. Reverse transcription polymerase chain reaction (RT-PCR) experiments of total RNA from blood lymphocytes were performed. The amplification of exons 3 and 4 of the pathogenic gene were amplified and identified by agarose gel. The expression of the pathogenic gene was also detected.Results:Three affected males of the family were diagnosed with SEDT according to their clinical and radiological features. A nonsense mutation in the transport protein particle complex subunit 2 ( TRAPPC2) gene NM_001011658: c.91A>T (p.K31*) was found in the proband using whole exome sequencing. This variation was also detected in his cousin, but not in non-phenotypic members of the family. The RT-PCR result for amplification of exon 3 and 4 of peripheral blood lymphocytes was the same as those of normal controls, indicating that the mutation did not affect the splicing of transcripts. qPCR results showed that the transcriptional expression of TRAPPC2 in patients was significantly lower than that in family normal controls and normal people controls. Conclusion:Identification of the novel nonsense mutation (c.91A>T) in the SEDT family enables early patients screening, carrier detection, genetic counseling, prenatal diagnosis, and clinical prevention and treatment. The detailed genotype/phenotype descriptions contribute to the SEDT mutation spectrum. The study of the function of TRAPPC2 mutation will help to further elucidate the role of sedlin in cartilage.

OBJECTIVE: To explore the genetic basis for a Chinese pedigree affected with dyschromatosis symmetrica hereditaria (DSH). METHODS: PCR and Sanger sequencing were carried out for the proband, and suspected variant was validated by Sanger sequencing in the pedigree. RESULTS: The proband was found to harbor a novel variant of c.1352delA (p.N451Mfs*13) of the ADAR (NM_001111) gene. The same variant was found in her affected mother and sister, but not in her unaffected father, uncle, and 100 healthy individual. CONCLUSION The novel variant of the ADAR gene probably underlay the pathogenesis of DSH in this pedigree.
Adenosine Deaminase/genetics* ; China ; Female ; Humans ; Mutation ; Pedigree ; Pigmentation Disorders/congenital* ; RNA-Binding Proteins/genetics*

OBJECTIVE: To explore the genetic basis for a couple who had developed polyhydramnios during three pregnancies and given birth to two liveborns featuring limb contracture, dyspnea and neonatal death. METHODS: Whole-exome sequencing (WES) was carried out on fetal tissue and peripheral blood samples from the couple. Suspected variants were verified by Sanger sequencing. RESULTS: The fetus was found to harbor homozygous nonsense c.3718C>T (p.Arg1240Ter) variants of the CNTNAP1 gene, which were respectively inherited from its mother and father. The variant was unreported previously. According to the guidelines of the American College of Medical Genetics and Genomics, the variant was predicted to be pathogenic (PVS1+PM2+PP4). CONCLUSION The novel homozygous nonsense variants of the CNTNAP1 gene probably underlay the lethal congenital contracture syndrome type 7 (LCCS7) in this pedigree. Above finding has enabled genetic counseling and prenatal diagnosis for the family.
Cell Adhesion Molecules, Neuronal ; China ; Contracture/genetics* ; Female ; Humans ; Infant, Newborn ; Mutation ; Pedigree ; Pregnancy ; Whole Exome Sequencing

Prospective research have shown that whole exome sequencing (WES) may be considered when a diagnosis cannot be obtained using routine prenatal methods, e. g., chromosomal karyotyping and copy number variation sequencing, for fetuses with significant structural anomalies. WES can increase the diagnostic rate of genetic disorders in such fetuses by 8%~10%. Prenatal WES has been gaining wide acceptance. However, due to the limitations of fetal phenotypic evaluation and complexity of ethical issues in prenatal diagnosis, to justify and standardize the application of prenatal WES and maximize its clinical utility has become an urgent need. In view of this, a consensus has been formed by referring to the latest guidelines, expert consensus and authoritative literature. This consensus has put forward suggestions on the suitable objects of prenatal WES, pre-test consultation, sampling and laboratory testing, results report, post-test consultation, pregnancy outcome follow-up, multidisciplinary consultation of difficult cases, preservation of prenatal WES samples and data information.

Objective:To summarize the diagnosis features of the prenatal genetic diagnosis of fetal renal cystic disease and to explore the clinical feasibility and significance of prenatal genetic diagnosis of congenital cystic nephrosis.Methods:A total of 25 fetuses with congenital renal cystic disease were examined via invasive prenatal diagnosis in Henan Provincial People's Hospital from June 2017 to September 2019. Amniotic fluid samples were extracted by amniocentesis. Chromosomal microarray analysis (CMA) were performed in 17 cases. In addition to CMA, the other 8 cases were analyzed by G-band karyotype. Whole exome sequencing (WES) was performed in 6 cases which got normal results by CMA and karyotype, and highly suspected as hereditary disease.Results:Of the 25 fetuses assessed, 4 cases (16.0%) pathogenic copy number variation (pCNV) were found, including 2 cases of 17q12 deletion, 1 case of 10p15.1p14 deletion and 1 case of 4q21.28q22.1 deletion(including PKD2 gene). There were 8 cases without chromosome abnormality by karyotype analysis. Six clinical WES analysis found NPHS1 gene c.1440+1 G>A and c.925G > T mutations were related to Finnish type congenital nephrotic syndrome in 1 case, PKD1 gene c.6878C>T mutation was related to autosomal dominant polycystic kidney disease (ADPKD) in 1 case, and there was no definitive mutation in 4 cases. Conclusions:CMA and next generation sequencing are powerful tools for accurate diagnosis, treatment and genetic counseling of fetal congenital renal cystic diseases. For congenital cystic nephropathy, genetic detection is helpful to clarify the etiology, and provide more exactly informations for prognosis evaluation, treatment and family genetic counseling.

OBJECTIVE: To explore the genetic basis for a pedigree affected with hereditary spastic paraplegia type 4 (HSP4). METHODS: Peripheral venous blood samples were taken from members of the four-generation pedigree and 50 healthy controls for the extraction of genomic DNA. Genes associated with peripheral neuropathy and hereditary spastic paraplegia were captured and subjected to targeted capture and next-generation sequencing. The results were confirmed by Sanger sequencing. RESULTS: DNA sequencing suggested that the proband has carried a heterozygous c.1196C>G variant in exon 9 of the SPAST gene, which can cause substitution of serine by threonine at position 399 (p.Ser399Trp) and lead to change in the protein function. The same variant was also detected in other patients from the pedigree but not among unaffected individuals or the 50 healthy controls. Based on the ACMG 2015 guidelines, the variant was predicted to be possibly pathogenic. CONCLUSION The c.1196C>G variant of the SPAST gene probably underlay the HSP4 in this pedigree.
Base Sequence ; Humans ; Mutation ; Paraplegia/genetics* ; Pedigree ; Sequence Analysis, DNA ; Spastic Paraplegia, Hereditary/genetics* ; Spastin/genetics*

In 2014, the training of clinical medical genetics was included in the training sequence of resident standardized training in China. The standardized training of clinical geneticist in China started relatively late. As a whole, the training and qualification system of clinical hereditary physicians are still in the process of development and perfection. Based on "Rules for the training of department of medical genetics", basic medical genetics resident training system was established in Henan Provincial People's Hospital. Additionally, we took advantage of interactive online education platform, multiple disciplinary team, the analysis of positive case report, literature report and other teaching practices combined with the tutor system. After 4 years of exploration and practice, the program can quickly improve the residents' comprehensive ability, such as theoretical knowledge, professional literacy, clinical practice skills, and scientific research ability.

OBJECTIVE: To explore the genetic basis for a fetus suspected for congenital nephrotic syndrome of Finland (CNF). METHODS: Genomic DNA was extracted from peripheral and umbilical cord blood samples derived from both parents and the fetus. Potential variants were detected by using next-generation sequencing. Suspected variants were confirmed by Sanger sequencing. RESULTS: The fetus was found to carry compound heterozygous variants c.1440+1G>A and c.925G>T of the NPHS1 gene, which were respectively inherited from its mother and father. CONCLUSION Identification of the compound heterozygous NPHS1 variants has enabled diagnosis of CNF in the fetus and genetic counseling for the affected family.
Female ; Fetus ; Finland ; Heterozygote ; Humans ; Membrane Proteins ; genetics ; Nephrotic Syndrome ; congenital ; diagnosis ; Pregnancy ; Prenatal Diagnosis