Identification and analysis of anovel variant of TRAPPC2 in a X-linked spondyloepiphyseal dysplasia tarda pedigree / 中华骨科杂志

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.

Clinical characteristics and pathogenic gene analysis in a large pedigree with multiple epiphyseal dysplasia / 中华骨科杂志

Objective To provide experimental evidence for genetic counseling and prenatal molecular diagnosis by analyzing the clinical characteristics and screening for pathogenic genes of a five-generation suspected multiple epiphyseal dysplasia (MED) family (17 patients).Methods The family members' medical history,general physical examination and hip joint X-ray examination were collected.Peripheral blood samples of the family members were collected and DNA were extracted from these samples.The exons of clinical genes from probands' DNA were sequenced by High throughput sequencing method.Next Gene software was used to compare and analyze the sequence and INGENUITY software was further used to annotate the mutations in order to find the pathogenic mutations in probands.The suspicious mutations were confirmed in pedigree members by PCR and Sanger sequencing.Results The family consisted of 5 generations and 38 members.Pedigree analysis was consistent with autosomal dominant inheritance.There were 17 patients in the family,and their clinical manifestations showed abnormal walking posture in childhood,pain in hip and knee joints,and typical pathological changes of epiphyseal dysplasia on X-ray.Cartilage oligomeric matrix protein (COMP) gene c.1153G ＞ A (p.Asp385Asn) missense heterozygous mutation was screened in proband,which was genotypically and phenotypically segregated in the pedigree.Conclusion A missense mutation of the comp gene has been identified in a pedigree affected with MED which was the first reported in a big family.Our result is conducive to the further diagnosis and treatment and also provides a molecular basisfor the future prenatal diagnosis.

A case of hyaline fibromatosis syndrome caused by compound heterozygous mutations in the ANTXR2 gene / 中华皮肤科杂志

A female patient aged 7 years and 5 months presented with multiple skin defects of the scalp, ears, hands and in the sacrococcygeal region, and multiple joint flexion contractures of the extremities for more than 7 years. Skin examination showed skin defects of the scalp, auricles, hands and in the sacrococcygeal region, gingival swelling, and multiple joint flexion contractures of the extremities. Genetic testing of the peripheral blood revealed 2 compound heterozygous mutations c.1073delC (A359Lfs*51) and c.1073dupC (A359Cfs*13) in the anthrax toxin receptor-2 ( ANTXR2) gene in the patient, which were inherited from her mother and father respectively. The patient was diagnosed with hyaline fibromatosis syndrome. Surgical treatment was rejected, and anti-inflammatory drugs, analgesics and other drugs were administered for symptomatic treatment. During follow-up of half a year, the child occasionally had mild diarrhea, and other symptoms did not progress markedly.

Clinical characteristics and pathogenic gene analysis in a large pedigree with multiple epiphyseal dysplasia / 中华骨科杂志

Objective@#To provide experimental evidence for genetic counseling and prenatal molecular diagnosis by analyzing the clinical characteristics and screening for pathogenic genes of a five-generation suspected multiple epiphyseal dysplasia (MED) family (17 patients).@*Methods@#The family members' medical history, general physical examination and hip joint X-ray examination were collected. Peripheral blood samples of the family members were collected and DNA were extracted from these samples. The exons of clinical genes from probands' DNA were sequenced by High throughput sequencing method. Next Gene software was used to compare and analyze the sequence and INGENUITY software was further used to annotate the mutations in order to find the pathogenic mutations in probands. The suspicious mutations were confirmed in pedigree members by PCR and Sanger sequencing.@*Results@#The family consisted of 5 generations and 38 members. Pedigree analysis was consistent with autosomal dominant inheritance. There were 17 patients in the family, and their clinical manifestations showed abnormal walking posture in childhood, pain in hip and knee joints, and typical pathological changes of epiphyseal dysplasia on X-ray. Cartilage oligomeric matrix protein (COMP) gene c.1153G>A (p.Asp385Asn) missense heterozygous mutation was screened in proband, which was genotypically and phenotypically segregated in the pedigree.@*Conclusion@#A missense mutation of the comp gene has been identified in a pedigree affected with MED which was the first reported in a big family. Our result is conducive to the further diagnosis and treatment and also provides a molecular basisfor the future prenatal diagnosis.

Identification of SPAST gene variant in a pedigree affected with hereditary spastic paraplegia type 4 / 中华医学遗传学杂志

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.

Analysis of MYO7A gene mutation in a family with non-syndromic autosomal recessive deafness / 中华医学遗传学杂志

Objective@#To explore the genetic basis for a family with non-syndromic autosomal recessive deafness.@*Methods@#The proband and her parents were subjected to physical and audiological examinations. With genomic DNA extracted from peripheral blood samples, next-generation sequencing was carried out using a panel for deafness genes. Suspected mutation was validated by Sanger sequencing and qPCR analysis of her parents.@*Results@#The proband presented bilateral severe sensorineural hearing loss at three days after birth. Her auditory threshold was 110-120 dBnHL but with absence of vestibular and retinal symptoms. Her brother also had deafness but her parents were normal. No abnormality was found upon physical examination of her family members, while audiological examination showed no middle ear or retrocochlear diseases. Next-generation sequencing identified compound heterozygous mutations of the MYO7A gene, including a previously known c. 462C>A (p. Cys154Ter) and a novel EX43_46 Del, which were respectively derived from her mother and father.@*Conclusion@#The compound heterozygous mutations of the MYO7A gene probably underlie the disease in this family. Our findings has enriched the mutation spectrum for non-syndromic autosomal recessive deafness 2.

Prenatal diagnosis of a fetus affected with Finnish type congenital nephrotic syndrome / 中华医学遗传学杂志

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.

Identification of two novel Parkin gene mutations in a patient affected with Juvenile Parkinson's syndrome / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical and genetic features of a patient suspected with Juvenile Parkinson's syndrome (JP).@*METHODS@#Clinical features of the patient were analyzed. Genomic DNA of the patient and his parents was extracted from peripheral blood samples and sequenced by exome capture sequencing. The nature and impact of detected mutations were predicted and validated.@*RESULTS@#The patient displayed typical features including resting tremor, bradykinesia, rigidity, but with excellent response to low dose levodopa. DNA sequencing showed that she has carried compound heterozygous mutations of the Parkin gene, namely c.1381dupC and c.619-1G>C, which were respectively inherited from his mother and father. Neither mutation was reported previously. Bioinformatic analysis predicted that both mutations are pathogenic.@*CONCLUSION@#The patient has JP caused by mutations of the Parkin gene. Exome capture sequencing is an accurate and efficient method for genetic diagnosis of such disease.

Prenatal diagnosis of a fetus affected with Finnish type congenital nephrotic syndrome / 中华医学遗传学杂志

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.

Analysis of MYO7A gene mutation in a family with non-syndromic autosomal recessive deafness / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a family with non-syndromic autosomal recessive deafness.@*METHODS@#The proband and her parents were subjected to physical and audiological examinations. With genomic DNA extracted from peripheral blood samples, next-generation sequencing was carried out using a panel for deafness genes. Suspected mutation was validated by Sanger sequencing and qPCR analysis of her parents.@*RESULTS@#The proband presented bilateral severe sensorineural hearing loss at three days after birth. Her auditory threshold was 110-120 dBnHL but with absence of vestibular and retinal symptoms. Her brother also had deafness but her parents were normal. No abnormality was found upon physical examination of her family members, while audiological examination showed no middle ear or retrocochlear diseases. Next-generation sequencing identified compound heterozygous mutations of the MYO7A gene, including a previously known c.462C>A (p. Cys154Ter) and a novel EX43_46 Del, which were respectively derived from her mother and father.@*CONCLUSION@#The compound heterozygous mutations of the MYO7A gene probably underlie the disease in this family. Our findings has enriched the mutation spectrum for non-syndromic autosomal recessive deafness 2.

Analysis of pathological mutation in a Chinese pedigree affected with familial exudative vitreoretinopathy / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To detect potential mutation in a Chinese pedigree affected with familial exudative vitreoretinopathy (FEVR).</p><p><b>METHODS</b>Clinical data of the pedigree was collected. Coding regions of candidate genes were amplified by PCR and subjected to next generation sequencing (NGS). Suspected mutations were verified by Sanger sequencing and segregation analysis.</p><p><b>RESULTS</b>Two novel heterozygous mutations (c.1695dupC and c.552-563del) were respectively detected in the LRP5 and ZNF408 genes in the proband. Both mutations were inherited from the affected mother. By Sanger sequencing, the c.552-563del mutation was also detected among unaffected members, while the c.1695dupC mutation was only detected in affected members from the pedigree and was not recorded by the HGMD, NCBI, or 1000 genome database. Upon prenatal diagnosis, the fetus was found to carry the same mutations.</p><p><b>CONCLUSION</b>Combined NGS and Sanger sequencing not only can reduce the time required for diagnosis but also enable accurate prenatal diagnosis for FEVR.</p>

Identification of a novel EXT1 mutation in a pedigree affected with hereditary multiple exostosis / 中华医学遗传学杂志

OBJECTIVE To detect potential mutations of the EXT1 and EXT2 genes in a pedigree affected with hereditary multiple exostosis (HME). METHODS For a four-generation family with 7 affected individuals from 17 family members,genomic DNA was extracted from peripheral venous blood samples. All exons of the EXT1 and EXT2 genes were screened for potential mutation by PCR and Sanger sequencing. RESULTS A novel heterozygous frameshift mutation c.1202delT (p.I401Tfs*2)was found in exon 4 of the EXT1 gene in the proband and the other 6 affected individuals. The same mutation was not detected among the healthy members from the family. The mutation has given rise a truncated EXT1 protein with loss of 345 amino acids. CONCLUSION A novel frameshift mutation of the EXT1 gene has been identified in a pedigree affected with HME, which has enriched the mutational spectrum of the EXT1 gene and may facilitate genetic counseling and prenatal diagnosis for the family.

Phenotypic and genetic analysis of a child carrying a 17q11.2 microdeletion / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To analyze a child with facial abnormalities with combined cytogenetic and molecular techniques and delineate its clinical phenotype.</p><p><b>METHODS</b>Neuropsychological profile of the child was analyzed. Color Doppler, CT and MRI were used for detecting the nodules in the body. Conventional peripheral blood karyotypes of the child and his parents were analyzed with G-banding. Array-comparative genomic hybridization (aCGH) was performed to detect minor structural chromosomal abnormalities.</p><p><b>RESULTS</b>The child had mental retardation, maxillofacial dysmorphism on the right side, and irregular solid nodules on the back. The karyotypes of the child and his parents were all normal, while aCGH has identified a de novo constitutive 1.2 Mb deletion at 17q11.2 in the child. The aCGH results of his parents were normal.</p><p><b>CONCLUSION</b>The de novo 17q11.2 microdeletion probably underlies the facial abnormalities and neurofibromatosis in the patient.</p>

Phenotypic and genetic analysis of a child featuring multiple malformations due to chromosome 14q deletion / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To analyze a child with mental retardation, growth retardation and language development disorders.</p><p><b>METHODS</b>Conventional G-banding analysis was performed on chromosomes cultivated from peripheral blood samples derived from the child and her parents. Array-comparative genomic hybridization (aCGH) was performed to detect minor structural chromosomal abnormalities, and the result was confirmed by short tandem repeats (STR) analysis.</p><p><b>RESULTS</b>For the child and her parents, no karyotypic abnormality was detected. However, aCGH analysis has identified a 14q22.1 deletion in the child. The microdeletion, with a size of 2.9 Mb was confirmed by STR analysis.</p><p><b>CONCLUSION</b>The 2.9 Mb chromosomal microdeletion probably underlies the mental retardation, growth retardation and language development disorders in the child.</p>

Analysis of PRRT2 gene mutations in a Chinese family affected with paroxysmal kinesigenic dyskinesia / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To screen potential mutations of PRRT2 gene in a Chinese family affected with paroxysmal kinesigenic dyskinesia (PKD).</p><p><b>METHODS</b>Polymerase chain reaction, DNA sequencing and restriction endonuclaese analysis were used to analyze all members of the family.</p><p><b>RESULTS</b>A heterozygous mutation c.649dupC was identified in the PRRT2 gene in all patients, while no similar mutation was found in healthy members from the family.</p><p><b>CONCLUSION</b>The c.649dupC mutation of the PRRT2 gene probably underlies the PKD in this family. Prenatal diagnosis can reduce the risk for further birth of affected children for this family.</p>

Mutation analysis of a Chinese family with Alport syndrome and genetic diagnosis before embryo implantation / 中华实用儿科临床杂志

Objective To study the gene mutation of a Chinese family with Alport syndrome and to perform preimplantation genetic diagnosis before embryo implantation.Methods Next generation sequence analysis was done for checking COL4A3,COL4A4 and COL4A5 genes in the Alport syndrome family members.Array comparative genomic hybridization(CGH) was used to detect the embryos.Results A mutation c.2605G ＞ A was found and identified in COL4A5 gene of all of the Alport syndrome patients in the family,but COL4A3 and COL4A3 genes were normal in all of the detected people.After searching for the mutation database,the mutation c.2605G ＞ A of COL4A5 gene was related to the X-linked dominant Alport syndrome.Three embryos were detected by using the preimplantation genetic diagnosis.Among these embryos,there were two male and one female.One of the male embryos was chromosomal aneuploidy,which was 45,XY,-16 and the other was normal.This normal embryo was implanted,and after 20 weeks the prenatal amniocentesis diagnosis approved that the fetus was normal.Conclusions The mutation of COL4A5 gene (c.2605 G ＞ A) is the cause of Alport syndrome in this family,which indicates that next generation sequence analysis proves to be an accurate and rapid method to detect Alport syndrome disease.Meanwhile array CGH can be used to reduce birth rates as a useful preimplantation genetic diagnosis method.

Phenotypic and genetic analysis of a girl with multiple congenital deformities due to 2p15-p16.1 microdeletion syndrome / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To determine the origin of chromosomal aberration for a girl with mental retardation and multiple congenital deformities.</p><p><b>METHODS</b>The karotypes of the girl and her parents were analyzed with routine G-banding .Their genomic DNA was also analyzed with array comparative genomic hybridization (aCGH). Short tandem repeats (STR) were used to confirm the results of aCGH.</p><p><b>RESULTS</b>There were no karyotypic abnormality detected at cytogenetic level. aCGH identified a de novo 1.28 Mb deletion at 2p15-p16.1 in the girl. The results of the STR confirmed the deletion affected the maternal chromosome.</p><p><b>CONCLUSION</b>The de novo interstitial 2p15-p16.1 deletion may cause the mental retardation and multiple congenital deformities. chr2:60.5-61.5 Mb may be the minimal common region of 2p15-p16.1 microdeletion syndrome.</p>

Mutation analysis and prenatal diagnosis of COL1A1 gene in a Chinese family with type I osteogenesis imperfecta / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To detect mutation of COL1A1 gene in a Chinese family affected with type I osteogenesis imperfecta (OI) and to provide prenatal diagnosis for a fetus at 17th gestational week.</p><p><b>METHODS</b>Polymerase chain reaction, DNA sequencing and restriction endonuclease analysis were used to verify the detected mutation among other members of the family and 100 healthy controls.</p><p><b>RESULTS</b>No mutation has been detected in the COL1A2 gene in all of the subjects. A heterozygous mutation c.104-1G>C was identified in the COL1A1 gene among all patients from this family. The same mutation was not found in other members from the family and the 100 healthy controls. The mutation was not found in the fetus, and was verified to be a new mutation according to the type I collagen mutation database.</p><p><b>CONCLUSION</b>The c.104-1G>C mutation of the COL1A1 gene probably underlies the type I osteogenesis imperfecta in this family. Under the premise of a clear genetic diagnosis, prenatal diagnosis may be provided to reduce the risk for the disease.</p>