Analysis of gene variant in an infant with succinic semialdehyde dehydrogenase deficiency / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a child with succinate semialdehyde dehydrogenase deficiency.@*METHODS@#Peripheral blood samples of the proband and his parents were collected and subjected to Sanger sequencing. High-throughput sequencing was used to verify the gene variants. Bioinformatic software was used to analyze the pathogenicity of the variant sites.@*RESULTS@#Sanger sequencing showed that the proband carried a homozygous c.1529C>T (p.S510F) variant of the ALDH5A1 gene, for which his mother was a carrier. The same variant was not detected in his father. However, high-throughput sequencing revealed that the child and his father both had a deletion of ALDH5A1 gene fragment (chr6: 24 403 265-24 566 986).@*CONCLUSION@#The c.1529C>T variant of the ALDH5A1 gene and deletion of ALDH5A1 gene fragment probably underlay the disease in the child. High-throughput sequencing can detect site variation as well as deletion of gene fragment, which has enabled genetic diagnosis and counseling for the family.

Analysis of cytogenetic characteristics of 321 children with hypospadias and literature review / 中华泌尿外科杂志

Objective:To explore the cytogenetic characteristics of hypospadias in children by karyotype analysis.Methods:From June 2008 to May 2018, 45 children with hypospadias in Tianjin Children's Hospital had cytogenetic abnormalities. Their median age was 10 months(range 3 hours to 5 years old). Of the 45 cases, 20 were proximal hypospadias, 1 was middle hypospadias. All 24 cases had varying degrees of genitourinary malformations. Among them, 15 cases had unilateral or bilateral cryptorchidism, 5 cases had scrotal division, 3 cases had penile scrotal transposition, 3 cases had small penis, 3 cases had indirect inguinal hernia, 1 case had repeated urethra, 1 case had hydrocele and 1 case had concealed penis. To the other systemic malformations, there was 1 with cleft lip and palate and 1 with congenital heart disease. G-banding karyotype analysis of peripheral blood lymphocytes was performed in all 45 cases.Results:Among the 45 cases of hypospadias with abnormal karyotypes, with an abnormal rate of 14.0%, 28 cases (62.22%) had sex chromosome abnormalities, including (47, XXY), (46, XX/47, XXY), (45, X0/47, XYY), etc. Sexual inversion occurred in 8 cases (17.78%), all of which were 46, XX. There were 4 autosomal abnormalities (8.89%), including (46, XY, 9p+ ), (46, XY, 10p+ ) and (46, XY, 1q+ ). Chromosome polymorphism was found in 4 cases (8.89%), including [46, XY, inv(9)] and [46, XY, 16qh+ ], and the equilibrium translocation of 1 case (2.22%) was [45, XY, -21, -22, + t(21; 22)]. Among the 45 cases, 8 sex reversal children with (46, XX) chromosome karyotype were all proximal hypospadias.Conclusions:Children with hypospadias may be associated with chromosomal karyotype abnormalities, including sex chromosomal abnormalities, autosomal abnormalities, chromosome polymorphism and balanced translocation. Among them, sex chromosome abnormality was the most common and balanced translocation was the least.

Study on DNA methylation in three neural tube defects pedigrees / 中华实用儿科临床杂志

Objective To investigate the methylation alteration of genomic DNA (gDNA) and its significance in pedigree neural tube defects (NTDs).Methods Twelve subjects from 3 NTDs pedigrees were enrolled in this study.NTDs patients were served as the case group,and their family members with normal phenotype were served as the control group.Peripheral vein blood was extracted,then gDNA was extracted.The extracted gDNA was treated with sodium bisulfite propagated as DNA segments in the way of whole genome amplification,which was put in I11umina Infinium human methylation 450k bead chip to perform hybridization,elution,extension,and imaging.The chip was scanned by iScan.Genome Studio was used to read the outcome.Illumina methylation analyzer software was used to analyze the methylation data.Results Gene differential methylation analysis showed that differential methylation sites only accounted for 0.2％ of the detected CpG sites and there were 617 differential hypermethylation sites (P ＜ 0.05),and 63 of them represented significant difference(P ＜ 1 × 10-4),including zinc finger E-box binding homebox 2,5,10-methylenetetrahydrofolate dehydrogenase 1 etc;there were 104 differential hypomethylation sites (P ＜ 0.05),and 65 of them represented significant difference (P ＜ 0.01),including Homeobox B7 and runt-related transcription factor 3 etc.Clustering analysis indicated that the tendency of DNA hypermethylation was consistent with NTDs patients,but the tendency of DNA hypomethylation was consistent with the controls.Conclusion In NTDs pedigree,the abnormal DNA methylation alterations may be the risk factor for NTDs occurrence.

Mutation analysis on DACT1 gene in children with neural tube defects in northern Chinese Han population / 天津医药

Objective To investigate the correlation between neural tube defects (NTDs) and DACT1 gene, and provide the basic data for disease diagnosis and genetic counseling. Methods Blood samples were obtained from 163 NTDs patients and 480 unrelated healthy individuals. Mutation detection of DACT1 gene and DNA direct sequencing was carried out by PCR amplification. Bioinformatics analysis of these mutated loci was performed. Results Six mutations were found in NTDs patients, including 4 missense mutations (p.R45W, p.D142G, p.N356K and p.V702G). But these mutations were not found in 480 healthy individuals. Three mutated amino acid residues (p.45R, p.142D and p.356N) were highly conservative in evolution, and the mutated carriers were female patients, and suffered from anencephaly. Conclusion DACT1 gene mutation may be a risk factor of NTDs in Han population of northern China.

Study on DNA methylation in three neural tube defects pedigrees / 中华实用儿科临床杂志

Objective To investigate the methylation alteration of genomic DNA (gDNA) and its significance in pedigree neural tube defects (NTDs).Methods Twelve subjects from 3 NTDs pedigrees were enrolled in this study.NTDs patients were served as the case group,and their family members with normal phenotype were served as the control group.Peripheral vein blood was extracted,then gDNA was extracted.The extracted gDNA was treated with sodium bisulfite propagated as DNA segments in the way of whole genome amplification,which was put in I11umina Infinium human methylation 450k bead chip to perform hybridization,elution,extension,and imaging.The chip was scanned by iScan.Genome Studio was used to read the outcome.Illumina methylation analyzer software was used to analyze the methylation data.Results Gene differential methylation analysis showed that differential methylation sites only accounted for 0.2％ of the detected CpG sites and there were 617 differential hypermethylation sites (P ＜ 0.05),and 63 of them represented significant difference(P ＜ 1 × 10-4),including zinc finger E-box binding homebox 2,5,10-methylenetetrahydrofolate dehydrogenase 1 etc;there were 104 differential hypomethylation sites (P ＜ 0.05),and 65 of them represented significant difference (P ＜ 0.01),including Homeobox B7 and runt-related transcription factor 3 etc.Clustering analysis indicated that the tendency of DNA hypermethylation was consistent with NTDs patients,but the tendency of DNA hypomethylation was consistent with the controls.Conclusion In NTDs pedigree,the abnormal DNA methylation alterations may be the risk factor for NTDs occurrence.