CONCLUSION The heterozygous variant of the HEPACAM gene probably underlies the MLC2B in this child. The variant has derived from her asymptomatic mother, which suggested incomplete penetrance of the MLC2B.OBJECTIVE To explore the genetic basis of a proband with distinctive facial features, global developmental delay, seizures and hypoplasia of corpus callosum through next generation sequencing (NGS). METHODS Genomic DNA was extracted from peripheral blood samples of the proband and his family members. Whole exome and flanking sequences were screened by NGS. Suspected variants were verified by Sanger sequencing. RESULTS The proband was found to carry a heterozygous c.2824G>T (p.G942X) variant of the ZEB2 gene, which was verified by Sanger sequencing to be a de novo variant. CONCLUSION The heterozygous c.2824G>T (p.G942X) variant of the ZEB2 gene probably underlies the Mowat-Wilson syndrome in the proband.OBJECTIVE To detect pathogenic variant in a juvenile with severe type Cornelia de Lange syndrome (CdLS). METHODS A 12-year-old female presented with comprehensive developmental retardation and deformity of lower limbs. Genomic DNA was extracted from peripheral blood sample of the patient. Whole exome sequencing was performed to identify pathogenic variants. Putative variant was verified by Sanger sequencing. The impact of variants was predicted and validated by bioinformatic analysis. RESULTS A de novo missense variant, c.1507A>G (p. Lys503Glu), was found in the NIPBL gene of the proband. The variant was unreported previously and predicted to be pathogenic by PolyPhen-2, MutationTaster and SIFT. Using HomoloGene system, the 503 loci in the NIPBL protein are highly conserved. The change of amino acid (Glu), locating in 503 locus, was found to cause the Neuromodulin_N superfamily domain destroyed, resulting in severe damage to the function of NIPBL protein. CONCLUSION The de novo missense variant c.1507A>G (p. Lys503Glu) of the NIPBL gene probably underlies the disease in this patient.OBJECTIVE To delineate the nature and origin of chromosomal aberration in a boy with mental retardation and multiple congenital deformities. METHODS Chromosomal karyotypes of the proband and his parents were determined by routine G-banding analysis. Genomic DNA was also analyzed with single nucleotide polymorphism array (SNP array). RESULTS The karyotype of the proband was 46,X,add(Y)(q11.23). No karyotypic abnormality was detected in either parent. SNP array has identified a de novo 21.6 Mb duplication at 22q12qter in the proband. CONCLUSION The de novo 22q12qter duplication probably underlies the abnormalities in the proband.OBJECTIVE To summarize newborn screening for methionine adenosyltransferase I/III (MAT I/III) deficiency in Quanzhou region of Fujian Province. METHODS A total of 364 545 neonates were screened for inherited metabolic diseases by tandem mass spectrometry. High-throughput next generation sequencing combined with Sanger sequencing was used to detect potential variants in newborns with MAT I/III deficiency. Pathogenicity of suspected variants was predicted by using MutationTaster and HSF software. RESULTS Three newborns were identified with MAT I/III deficiency by newborn screening, which yielded an incidence rate of 1 in 121 515. Amino acid and acylcarnitine analysis suggested that the serum methionine of the three patients have increased to various extents. All patients showed normal growth and development during follow-up, and were found to carry MAT1A gene variants including two missense variants [c.776C>T (p.Ala259Val) and c.791G>A (p.Arg264His)] and a synonymous variant [c.360C>T (p.Cys120Cys)]. Among these, c.776C>T (p.Ala259Val) and c.791G>A (p.Arg264His) were known to be pathogenic, whereas c.360C>T (p.Cys120Cys) was a novel variant. Bioinformatics analysis suggested that this variant may alter RNA splicing and affect the structure and function of the MAT1A protein. CONCLUSION A systematic review of newborn screening for MAT I/III deficiency was provided. Discovery of the novel variant has enriched the variant profile of the MAT1A gene and provided a basis for the diagnosis of this disease.OBJECTIVE To explore the genetic basis for a couple with normal phenotype but repeated pregnancies with fetuses affected by osteogenesis imperfecta. METHODS Whole exome sequencing (WES) was carried out on fetal specimens and parental DNA to detect potential pathologic variants. Suspected variants were verified by Sanger sequencing. Semen sample of the husband was collected for the extraction of genome DNA, and whole genome amplification (WGA) was performed for single sperms isolated from the sample. RESULTS WES has identified a heterozygous c.1378G>A (p.G460S) variant of the COL1A2 gene in the fetus, which was predicted to be pathogenic but not detected in peripheral blood samples of both husband and wife. The heterozygotic variant was detected in semen DNA from the husband. Among 15 spermatozoa, 4 were found to harbor the variant. CONCLUSION The fetus was diagnosed with osteogenesis imperfecta, and the gonadal mosaicism probably accounted for the repeated abnormal pregnancies. Possibility of gonadal mosaicism should be considered when counseling couples with normal phenotype and genotype but recurrent abnormal pregnancies and/or births of children with similar phenotypes and genetic variants.OBJECTIVE To explore the molecular pathogenesis for a pedigree affected with hereditary coagulation factor XII (FXII) deficiency. METHODS Potential variant of the F12 gene was analyzed by PCR and Sanger sequencing. Expression plasmids were constructed by site-directed mutagenesis based on the wild-type and transiently transfected into 293T cells. FXIIC and FXIIAg of the expression products were determined in the supernatant and cell lysate. Western blotting was used to verify the identify of the protein. selleck chemicals llc RESULTS Gene sequencing revealed that the proband has carried 46TT genetype and heterozygous p.Glu502Lys variants in exon 13, and a heterozygous p.Gly542Ser variant in exon 14 of the F12 gene. Transfection experiment suggested that the FXIIC and FXIIAg of p.Glu502Lys variant in the supernatant were 28% and 24%, compared with the wild-type (100%) and FXIIAg of cell lysates was 39% compared to the wild-type (100%). The FXIIC and FXIIAg of p. Gly542Ser variant in the supernatant were 32% and 17% and the FXIIAg of cell lysates was 59%.