La variante SARS-CoV-2 subvariante ómicron BA4 y BA5 / SARS-CoV-2 subvariant omicron BA4 and BA5

Introducción: el día 26 de abril del año 2022, en México se anunció el final de la pandemia y el inicio de la fase endémica, ya que se cumplía con los criterios para considerar dicha transición, pero lo cierto es que existía la posibilidad de la aparición de nuevas olas de COVID-19 por nuevas variantes, esto provocado por factores como la movilización y la falta de vacunación en algunos grupos etarios, así como la disminución de medidas preventivas. Sin duda, estos factores han hecho que el fin de la fase pandémica aún sea lejano o cuando menos no a corto plazo. El propósito del estudio es presentar información de la aparición, ca- racterísticas y algunos datos de las subvariantes ómicron BA.4 y BA.5. Conclusiones: a pesar de estar en un proceso de pandemia a endemia, la aparición de nuevas olas de variantes y subvariantes de COVID-19 continuarán presentándose debido a la capacidad de mutación del virus y, por lo tanto, la inmunidad obtenida no será suficiente, se requiere un esfuerzo global del gobierno y la población para continuar con las medidas preventivas implementadas desde el inicio de la pandemia (AU)

Introduction: on 26 April 2022, in Mexico announced the end of the pandemic and the beginning of the endemic phase, since the criteria for considering this transition had been met. The truth is that the possibility of the appearance of new waves of COVID-19 due to new variants, caused by factors such as mobilisation, lack of vaccination in some age groups and the reduction of preventive measures, have undoubtedly made the end of the pandemic phase a long way off, or at least not in the short term. Undoubtedly, the end of the pandemic phase is still a long way off, or at least not in the short term. The purpose of the study is to present information on the emergence, characteristics and some data on the omicron BA.4 and BA.5 subvariants. Conclusions: despite being in a pandemic to endemic process, the emergence of new waves of COVID-19 variants and subvariants will continue to occur due to the mutational capacity of the virus and therefore the immunity obtained will not be sufficient, a global effort is required from the government and the population to continue with the preventive measures implemented since the beginning of the pandemic (AU))

Clinical phenotype and gene mutation analysis of 12 patients with hereditary protein C deficiency in different families / 中华血液学杂志

Objective: To investigate the molecular pathogenesis and clinical features of unrelated 12 patients with inherited coagulation protein C (PC) deficiency in Chinese population. Methods: The PC activity (PC:A) and PC antigen (PC:Ag) were detected by chromogenic substrate and enzyme linked immunosorbent assay, respectively. The nine exons and flanking sequences of the protein C (PROC) gene were amplified by polymerase chain reaction with direct sequencing, and the suspected mutations were validated by reverse sequencing (clone sequencing for deletion mutations) . Results: The PC:A of the 12 probands decreased significantly, ranging from 18% to 55%, and the PC:Ag of the 10 probands decreased significantly. Eleven mutations were found, out of which four mutations [c.383G>A (p.Gly128Asp) , c.997G>A (p.Ala291Thr) , c.1318C>T (p.Arg398Cys) , and c.532G>C (p.Leu278Pro) ] were discovered for the first time. Six mutations were in the serine protease domain, four mutations were located in epidermal growth factor (EGF) -like domains, and one mutation was located in activation peptide. There were two deletion mutations (p.Met364Trp fsX15 and p.Lys192del) , and the rest were missense mutations. Mutations p.Phe181Val and p.Arg189Trp were identified in three unrelated families. All mutations may be inherited, and consanguineous marriages were reported in two families. Among the probands, nine cases had venous thrombosis, two cases had poor pregnancy manifestations, and one case had purpura. Conclusion: Patients with PC deficiency caused by PROC gene defects are prone to venous thrombosis, especially when there are other thrombotic factors present at the same time.

Whole exome sequencing and analysis of hypohidrotic ectodermal dysplasia patients / 中华口腔医学杂志

Objective: To detect gene mutation in patients with hypohidrotic ectodermal dysplasia (HED) by using whole exome sequencing, to analyze the pathogenicity of the mutations, and to provide reference for the genetic diagnosis of HED patients. Methods: Peripheral blood genomic DNA was extracted from each of the HED patients and their family members collected in Peking University School and Hospital of Stomatology from August 2016 to August 2021. Whole exome sequencing and sanger sequencing were performed to detect gene mutations. Functions of the rare variants after the database filtering were analyzed by bioinformatics tools. Results: Three reported mutations of ectodysplasin A (EDA) gene (c.2T>C, c.161A>G, c.467G>A) and a mutation of ectodysplasin A receptor (EDAR) gene (c.871G>A) were detected by whole genome sequencing in four HED patients, and were verified by Sanger sequencing in four HED families. The EDAR gene mutation founded in this research was reported in HED patients for the first time. Bioinformatics tools predicted that the mutations of EDA gene detected in this study were highly species conserved and disease-causing. The combined annotation dependent depletion (CADD) scores of EDA gene mutations c.2T>C, c.161A>G and c.467G>A were 22.5, 26.3 and 25.5 respectively, and the genomic evolutionary rate profiling (GERP) scores were 2.16, 2.26 and 2.18 respectively. The EDAR gene mutation c.871G>A detected in this study was species conserved and possibly disease-causing. The CADD and GERP scores of EDAR gene mutation c.871G>A were 22.0 and 1.93 respectively. Conclusions: Three reported mutations of EDA gene and a previously unreported mutation of EDAR gene were detected in four HED families. Different mutations of EDA gene and EDAR gene could make different influence on the protein function and lead to the occurrence of HED.

A family of hereditary protein S deficiency with the onset of pulmonary embolism and literature review / 中华儿科杂志

Objective: To explore the clinical characteristics and genotype of PROS1 gene related hereditary protein S deficiency (PSD) with the onset of pulmonary embolism in children. Methods: A family with pulmonary embolism was diagnosed as hereditary PSD in the Department of Pediatrics of Peking University First Hospital in November 2020, and the clinical data, including clinical manifestations, laboratory tests, imaging and genetic results, were collected for a retrospective research. The family members were also screened for protein S activity and PROS1 gene mutations. A literature search with "PROS1" "protein S deficiency" "homozygous" and "complex heterozygous" as key words was conducted at PubMed, China National Knowledge Infrastructure, and Wanfang Data Knowledge Service Platform (up to October 2021). Case reports of patients with PROS1 gene homozygous or complex heterozygous variants and related clinical features, protein S activity, and genotype were reviewed and analyzed. Results: The proband, a 14-year-old girl, was admitted to the hospital for a 9-day history of coughing and a 4-day history of chest pain in November 2020. After admission, laboratory tests showed that D-dimer was 8.38 mg/L (reference:<0.24 mg/L). An urgent CT pulmonary angiography confirmed bilateral pulmonary embolism and right lower pulmonary infarction, while an ultrasonography showed deep vein thrombosis in her left leg. Further examination revealed that protein S activity was less than 10%. The proband's second sister, a 12-year-old girl, was admitted to the hospital in December 2020. Her protein S activity was 8% and an ultrasonography showed deep vein thrombosis in her right leg. The protein S activity of the proband's father and mother were 36% and 26%, respectively. Trio-whole-exome sequencing detected compound heterozygous PROS1 gene variants (c.-168C>T and c.200A>C (p.E67A)) for the proband and her second sister, that were inherited from her father and mother, respectively. The proband's third sister's protein S activity was 28%; she and the proband's grandfather both carried c.200A>C (p.E67A) variants. The proband and her younger sister were treated with rivaroxaban and responded well during the 3-month follow-up. A total of 1 Chinese report in literature and 18 English literature were retrieved and 14 patients with protein S deficiency caused by homozygous or complex heterozygous variants of PROS1 gene were enrolled, including 8 male and 6 female patients. The ages ranged from 4 days to 35 years. Three patients experienced fulminant purpura or severe intracranial hemorrhage in early neonatal-period, while the remaining 11 patients developed venous thromboembolism in adolescence. Protein S activity was examined in 11 patients, and all showed less than 10% of activity. Missense variants was the most common type of gene variants. Conclusions: For children with pulmonary embolism, if there are no clear risk factors for thrombosis, hereditary protein S deficiency should be considered, and protein S activity should be examined before oral anticoagulant drugs. If protein S activity is less than 10%, protein S deficiency caused by homozygous or complex heterozygous variants should be considered.

Clinical features and CACNA1A gene mutation in a family with episodic ataxia type 2 / 中南大学学报(医学版)

Episodic ataxia (EA) is a group of disorders characterized by recurrent spells of vertigo, truncal ataxia, and dysarthria. Episodic ataxia type 2 (EA2), the most common subtype of EA, is an autosomal dominant disease caused by mutation of the CACNA1A gene. EA2 has been rarely reported in the Chinese population. Here we present an EA2 family admitted to Xiangya Hospital in October 2018. The proband was a 22-year-old male who complained of recurrent spells of vertigo, slurred speech, and incoordination for 4 years. Brain magnetic resonance imaging (MRI) showed cerebellar atrophy. He had neuropsychological development disorder in childhood, and cognitive assessment in adulthood showed cognitive impairment. The proband's mother and grandmother had a similar history. Peripheral blood samples from the proband and family members were collected, and genomic DNA was isolated. Whole exome sequencing of the proband detected a heterozygous frameshift mutation c.2042_2043del (p.Q681Rfs*100) of CACNA1A gene. This mutation was verified in the proband and 2 family members using Sanger sequencing. One family member carrying this mutation was free of symptoms and signs, suggesting an incomplete penetrance of the mutation. We reported a variant c.2042_2043del of CACNA1A gene as the pathogenic mutation in a Chinese EA2 family for the first time. This case enriched the clinical spectrum of CACNA1A related EA2, and contributed to the understanding of clinical and genetic characteristics of EA2 to reduce misdiagnosis.

Genetic research progress in branchio-oto syndrome/ branchio-oto-renal syndrome / 中南大学学报(医学版)

Branchio-oto syndrome (BOS)/branchio-oto-renal syndrome (BORS) is a kind of autosomal dominant heterogeneous disorder. These diseases are mainly characterized by hearing impairment and abnormal phenotype of ears, accompanied by renal malformation and branchial cleft anomalies including cyst or fistula, with an incidence of 1/40 000 in human population. Otic anormalies are one of the most obvious clinical manifestations of BOS/BORS, including deformities of external, middle, inner ears and hearing loss with conductive, sensorineural or mix, ranging from mild to profound loss. Temporal bone imaging could assist in the diagnosis of middle ear and inner ear malformations for clinicians. Multiple methods including direct sequencing combined with next generation sequencing (NGS), multiplex ligation-dependent probe amplification (MLPA), or array-based comparative genomic hybridization (aCGH) can effectively screen and identify pathogenic genes and/or variation types of BOS/BORS. About 40% of patients with BOS/BORS carry aberrations of EYA1 gene which is the most important cause of BOS/BORS. A total of 240 kinds of pathogenic variations of EYA1 have been reported in different populations so far, including frameshift, nonsense, missense, aberrant splicing, deletion and complex rearrangements. Human Endogenous Retroviral sequences (HERVs) may play an important role in mediating EYA1 chromosomal fragment deletion mutations caused by non-allelic homologous recombination. EYA1 encodes a phosphatase-transactivator cooperated with transcription factors of SIX1, participates in cranial sensory neurogenesis and development of branchial arch-derived organs, then regulates the morphological and functional differentiation of the outer ear, middle ear and inner ear toward normal tissues. In addition, pathogenic mutations of SIX1 and SIX5 genes can also cause BOS/BORS. Variations of these genes mentioned above may cause disease by destroying the bindings between SIX1-EYA1, SIX5-EYA1 or SIX1-DNA. However, the role of SIX5 gene in the pathogenesis of BORS needs further verification.

Whole-exome sequencing in diagnosing 2 cases of Gitelman syndrome / 中南大学学报(医学版)

Two patients with Gitelman syndrome were admitted to the Department of Endocrinology, Third Xiangya Hospital of Central South University. The genomic DNA from the patients' peripheral blood was extracted and the whole-exome sequencing was performed to detect the possible mutations. The function of the mutation sites was analyzed by bioinformatics software. Through whole-exome sequencing and Sanger sequencing, we have found that 2 patients with Gitelman syndrome carried compound heterozygous mutations of SLC12A3 gene, which were c.486_490delTACGGinsA, p.R943W, p.D486N, and p.R928C. Among them, c.486_490delTACGGinsA insertion deletion mutation causes frame shift and protein truncation. The p.R943W, p.D486N, and p.R928C of SLC12A3 gene were predicted to be pathogenic mutations by SIFT, PolyPhen2, and Mutation Taster. These 4 mutations were all reported, but p.R943W was first reported in Chinese population. Gitelman syndrome is rare in clinic and the rate of missed diagnosis is high. Early genetic analysis in patients with Gitelman syndrome is helpful to determine the etiology and guide the treatment.

Analysis of A Pedigree with Hereditary Coagulation Factor Ⅻ Deficiency Caused by Compound Heterozygous Mutations / 中国实验血液学杂志

OBJECTIVE@#To analysis clinical phenotype and potential genetic cause of a family affected with hereditary coagulation factor Ⅻ deficiency.@*METHODS@#The prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FIB), D-Dimer (D-D), coagulation factor Ⅻ activity (FⅫ:C) and coagulation factor Ⅻ antigen (FⅫ:Ag) were determined for phenotype diagnosis of the proband and his family members(3 generations and 5 people). Targeted capture and whole exome sequencing were performed in peripheral blood sample of the proband. Possible disease-causing mutations of F12 gene were obtained and further confirmed by Sanger sequencing. The corresponding mutation sites of the family members were analyzed afterwards. The online bioinformatics software AutoPVS1 and Mutation Taster was used to predict the effects of mutation sites on protein function.@*RESULTS@#The APTT of the proband was significantly prolonged, reaching 180.9s. FⅫ:C and FⅫ:Ag of the proband was significantly reduced to 0.8% and 4.17%, respectively. The results of whole exome sequencing displayed that there were compound heterozygous mutations in F12 gene of the proband, including the c.1261G＞T heterozygous nonsense mutation in exon 11 (causing p.Glu421*) and the c.251dupG heterozygous frameshift mutation in exon 4 (causing p.Trp85Metfs*53). Both mutations are loss of function mutations with very strong pathogenicity, leading to premature termination of the protein. AutoPVS1 and Mutation Taster software predicted both mutations as pathogenic mutations. The results of Sanger sequencing revealed that c.1261G＞T heterozygous mutation of the proband was inherited from his mother, for which his brother and his daughter were c.1261G＞T heterozygous carriers. Genotype-phenotype cosegregation was observed in this family.@*CONCLUSION@#The c.1261G＞T heterozygous nonsense mutation in exon 11 and the c.251dupG heterozygous frameshift mutation in exon 4 of the F12 gene probably account for coagulation factor Ⅻ deficiency in this family. This study reports two novel pathogenic F12 mutations for the first time worldwide.

Genetic Analysis and Prenatal Diagnosis of a Family with Hereditary Spherocytosis Caused by a Novel Compound Heterozygous Mutation of SPTB Gene / 中国实验血液学杂志

OBJECTIVE@#To investigate the clinical and genetic characteristics of a family with hereditary spherocytosis (HS), to clarify the cause of the disease, and to provide the basis for genetic counseling and prenatal diagnosis.@*METHODS@#The clinical data of proband and his parents were collected, and HS-related pathogenic genovariation of the proband was detected by high throughput sequencing. Suspected pathogenic mutation sites were verified by PCR-Sanger sequencing, and the fetus were conceived by a proband mother underwent prenatal diagnosis.@*RESULTS@#Clinical manifestations of the proband showed moderate anemia, mild splenomegaly, and jaundice (an indirect increase of bilirubin). The gene detection showed that the proband showed compound heterozygous mutations of SPTB gene c. 6095T > C (p.Leu2032Pro) and c. 6224A > G (p.Glu2075Gly), which was inherited from the asymptomatic mother and father, respectively. Both mutations were detected rarely in the common population. Prenatal diagnosis revealed that the fetus inherited a mutant gene of the mother.@*CONCLUSION@#The compound heterozygous mutations of SPTB genes c.6095T>C (p.Leu2032Pro) and c.6224A>G (p.Glu2075Gly) were the causes of the family disease, which provides a basis for family genetic counseling and prenatal diagnosis. This report is the first one found in the HGMD,1000G and EXAC database, which provides an addition to the mutation profile of the SPTB gene.

Variation of COL7A1 gene in dystrophic epidermolysis bullosa pruriginosa / 中华医学遗传学杂志

OBJECTIVE@#To perform gene mutation analysis in a Chinese pedigree with dystrophic epidermolysis bullosa pruriginosa (DEB-Pr), and explore phetotype, genotype, and genotypes-phenotypes relationship of DEB-Pr.@*METHODS@#Potential variants of the COL7A1 gene were detected by skin targeted sequencing panel and verified by Sanger sequencing. The pathogenicity of the variation was analyzed.@*RESULTS@#Compound heterozygous variants, c.4128delT and c.8234G>A, were detected in the COL7A1 gene of the two patients. The c.4128delT(p.Pro1376fs) variant was derived from their mother and unreported previously. According to the American College of Medical Genetics and Genomics Standards and Guidelines, it was suggested to be a pathogenic mutation. The c.8234G>A(p.Arg2745Gln) variant was derived from their father, and possibly is a pathogenic variation.@*CONCLUSION@#In this study, the compound heterozygous variants of c.4128delT(p.Pro1376fs) and c.8234G>A(p.Arg2745Gln) of the COL7A1 gene probably underlies the disease in this patient and his sister. And our study expands the database on mutations of DEB-Pr.

Analysis of phenotype and FH gene variation in a pedigree affected with hereditary leiomyomatosis and renal cell carcinoma syndrome / 中华医学遗传学杂志

OBJECTIVE@#To analyze clinical phenotype and genetic variants in a Chinese pedigree of hereditary leiomyomatosis and renal cell carcinoma (HLRCC) syndrome.@*METHODS@#Whole exome sequencing was carried out for the proband from the pedigree. Suspected FH gene variants were validated by Sanger sequencing. Clinical manifestation and histopathological examination were used to analyze the pedigree comprehensively.@*RESULTS@#The pedigree met the clinical diagnostic criteria for HLRCC syndrome. The whole exome sequencing showed that the FH gene of the proband had a heterozygous missense variant of c.1490T>C (p.F497S), which was consistent with the Sanger sequencing. The mother, daughter and son of the proband all had the heterozygous missense variant of c.1490T>C (p.F497S). According to the American Society of Medical Genetics and Genomics Classification Standards and Guidelines for Genetic Variations, c.1490T>C (p.F497S) (PM2+PP1-M+PP3+PP4) was a possible pathogenic variant. Based on our literature search, this variant was a new variant that had not been reported.@*CONCLUSION@#The FH gene missense variant of c.1490T>C (p.F497S) may be the cause of the HLRCC syndrome pedigree, which provides a basis for the genetic diagnosis and genetic counseling of the HLRCC syndrome.

Genetic diagnosis of 3 families with choroideremia / 中华医学遗传学杂志

OBJECTIVE@#To analyze the clinical manifestations and causative gene variants of the choroideremia patients, and to help the patients bedifferential diagnosed by whole exome sequencing and provide theoretical basis for their genetic counseling.@*METHODS@#Clinical data of 3 families were collected and genomic DNA was extracted respectively from peripheral blood of patients and related subjects. Exome targeted sequencing was used to screen suspicious gene mutations. Sanger sequencing and quantitative PCR were used to verify the candidate mutations and investigate the mutation carrying status of other members of the family. The candidate mutations were searched through HGMD and PubMed databases for the pathogenicity reports, and the pathogenicity of candidate mutations was judged according to a joint consensus recommendation of the American College of Medical Genetics and Genomics and the Association for Molecular Pathology.@*RESULTS@#The proband of family 1 is c.1584_1587del (p.Val529Hisfs*6) variant hemizygote, whose daughter carries c.1584_1587del (p.Val529Hisfs*6) heterozygous variation. The proband of family 2 is a hemizygote with deletion of exons 10 to 15 (E10-15del), and her mother and sister carry the E10-15del heterozygous variation. In family 3, the proband is c.544delT (p.Cys182Valfs*14) variant hemizygote, and his mother is c.544delT (p.Cys182Valfs*14) heterozygote, but the father do not detect this variant. All the 3 families were detected pathogenic gene variations of CHM, two of which were known pathogenic variation and one of which was novel CHM gene c.544delT (p.C182Vfs*14) in this study. The c.544delT frameshift mutation of CHM gene can lead to the premature termination of the product protein translation and nonfunctioning protein. It is a pathogenic mutation according to ACMG guidelines.@*CONCLUSION@#The findings of this study expand the gene variation spectrum of choroideremia.

Diagnosis and counseling for a Chinese pedigree affected with autosomal recessive primary microcephaly 5 due to variants of ASPM gene / 中华医学遗传学杂志

OBJECTIVE@#To detect potential mutation of the ASPM gene in a Chinese pedigree affected with autosomal recessive primary microcephaly 5 (MCPH5).@*METHODS@#Peripheral venous blood samples were collected from the proband and her parents. Amniotic fluid sample was also collected upon her mother' s subsequent pregnancy. Following extraction of genomic DNA, PCR and Sanger sequencing were carried out to identify potential variants of the ASPM gene.@*RESULTS@#The proband was found to harbor compound heterozygous variants of the ASPM gene, namely c.8214dupT (p.Q2739fs) in exon 18 and c.9541C>T (p.R3181X) in exon 23, which were respectively inherited from her father and mother. The fetus has found to have inherited the c.9541C>T (p.R3181X) variant only.@*CONCLUSION@#The c.8214dupT (p.Q2739fs) and c.9541C>T (p.R3181X) compound heterozygous variants of the ASPM gene probably underlay the pathogenesis of MCPH5 in this patient. Above finding has enabled genetic counseling and prenatal diagnosis for her family.

Genetic analysis of a Chinese pedigree affected with Becker muscular dystrophy with myalgia as the main feature / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis of a Chinese pedigree affected with Becker muscular dystrophy (BMD) with myalgia as the main feature.@*METHODS@#Clinical data of the patients and results of auxiliary examinations were retrospectively analyzed. Multiplex ligation-dependent probe amplification and high-throughput sequencing were used to detect potential variants. Sanger sequencing was used to verify the results.@*RESULTS@#The clinical manifestations of the proband included myalgia and elevated serum creatine kinase, which is similar to another patient from the pedigree. Genetic testing revealed that the two patients both harbored hemizygous deletions of exons 10 to 29 of the DMD gene, for which the mother was a carrier. The same deletion was not found in his father. Based on the guidelines from American College of Medical Genetics and Genomics, the deletion was predicted to be pathogenic (PVS1+PM2+PP1).@*CONCLUSION@#Myalgia with elevated serum CK may be atypical clinical manifestations of BMD and may be associated with variants in the rod domain of the DMD gene. The deletion of exons 10 to 29 of the DMD gene probably underlay the BMD in this pedigree.

Analysis of RS1 gene variant in a Chinese pedigree affected with X-linked congenital retinal splitters / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a Chinese pedigree affected with X-linked retinoschisis.@*METHODS@#Clinical data of the pedigree was collected. Following DNA extraction, PCR and Sanger sequencing were carried out to detect potential variant in the RS1 gene. The result was verified by using PCR and restriction fragment length polymorphism assay.@*RESULTS@#All male patients were found to harbor a c.458T>G (p.Val153Gly) variant of the RS1 gene, for which Their mothers were heterozygous carriers. The same variant was not detected among unaffected members of the pedigree as well as 100 healthy controls. Bioinformatic analysis suggested the variant to be pathogenic.@*CONCLUSION@#The c.458T>G (p.Val153Gly) variant of the RS1 gene probably underlay the X-linked retinoschisis in this pedigree.

Genetic analysis of a Chinese pedigree affected with branchiootic syndrome due to a nonsense variant of EYA1 gene / 中华医学遗传学杂志

OBJECTIVE@#To analyze the clinical phenotype and genetic basis for a Chinese pedigree suspected for branchiootic syndrome (BOS).@*METHODS@#The proband was subjected to target-capture high-throughput sequencing to detect potential variant of deafness-associated genes. Candidate variants were verified by Sanger sequencing of the family members.@*RESULTS@#The proband was found to harbor a c.1627C>T (p.Gln543Ter) nonsense variant of the EYA1 gene. Sanger sequencing confirmed that all of the 4 patients with the BOS phenotype from the pedigree have harbored the same heterozygous variant. Based on the guidelines of the American College of Medical Genetics and Genomics, the variant was predicted to be pathogenic (PVS1+PS+PP3+PP4).@*CONCLUSION@#The c.1627C>T (p.Gln543Ter) variant of the EYA1 gene probably underlay the BOS phenotype in this pedigree. Above finding has provided a basis for its clinical diagnosis.

Clinical and genetic analysis of a Chinese pedigree affected with Dyggve-Melchior-Clausen syndrome due to a novel frameshift variant of DYM gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis of a Chinese pedigree affected with Dyggve-Melchior-Clausen syndrome.@*METHODS@#Whole exome sequencing and Sanger sequencing were carried out to detect potential pathogenic variants associated with the syndrome. The function of candidate variant was verified by Western blotting.@*RESULTS@#A novel homozygous variant, c.1222delG of the DYM gene was detected in the two affected siblings, for which both parents were heterozygous carriers. The variant has caused replacement of Asp by Met at amino acid 408 and generate a premature stop codon p.Asp408Metfs*10. Western blotting confirmed that the variant can result in degradation of the mutant DYM protein, suggesting that it is a loss of function variant.@*CONCLUSION@#The homozygous c.1222delG frameshift variant of the DYM probably underlay the Dyggve-Melchior-Clausen syndrome in the two affected siblings. Above findings has enabled clinical diagnosis and genetic counseling for the family.