Analysis of a patient with tuberous sclerosis complex due to mosaicism TSC2 mutation / 中华医学遗传学杂志

OBJECTIVE@#To analyze variants of TSC1 and TSC2 genes in a Chinese patient with tuberous sclerosis complex (TSC).@*METHODS@#Peripheral blood samples were collected from the patient and her parents with informed consent. Following extraction of genomic DNA, potential variants of the TSC1 and TSC2 genes was detected by using targeted capture next-generation sequencing (NGS) and Sanger sequencing.@*RESULTS@#The patient was found to harbor a de novo mosaicism variant c.3295_3298delG (Val1100CysfsTer3) of the TSC2 gene, with the proportion of the mutant allele determined as 13.4%, which was confirmed by Sanger sequencing. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the c.3295_3298delG (Val1100CysfsTer3) variant was predicted to be pathogenic (PVS1+PS2+PM2).@*CONCLUSION@#The mosaicism heterozygous variant of c.3295_3298delG of the TSC2 gene, as detected by both NGS and Sanger sequencing, probably underlay the TSC2 in this patient.

Identification of a novel TSC2 gene variant in a patient with tuberous sclerosis complex / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a patient diagnosed with tuberous sclerosis complex (TSC).@*METHODS@#Peripheral blood samples of the patient and his parents were collected for the extraction of genomic DNA. Next generation sequencing (NGS) was carried out to detect potential variant, and the result was verified by Sanger sequencing.@*RESULTS@#The patient was found to harbor a heterozygous c.1053delG (p.Glu352SerfsX10) frameshifting variant of the TSC2 gene. The same variant was not found in his unaffected parents and 100 unrelated healthy controls. Based on the American College of Medical Genetics and Genomics guidelines, the variant was predicted to be pathogenic (PVS1+PS2+PM2).@*CONCLUSION@#The novel c.1053delG (p.Glu352SerfsX10) frameshifting variant of the TSC2 gene probably underlay the TSC in this patient.

A case of tuberous sclerosis complex due to a novel splicing variant of TSC2 gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a patient with tuberous sclerosis complex.@*METHODS@#Genomic DNA was extracted from peripheral blood samples from members of his family and 100 unrelated healthy controls. The proband was subjected to next-generation sequencing, and candidate variant was confirmed by multiple ligation-dependent probe amplification (MLPA) and Sanger sequencing. Reverse transcription-PCR (RT-PCR) was carried out to determine the relative mRNA expression in the proband.@*RESULTS@#The patient was found to harbor a c.2355+1G>C splicing variant of the TSC2 gene. Sequencing of cDNA confirmed that 62 bases have been inserted into the 3' end of exon 21, which has caused a frameshift producing a truncated protein.@*CONCLUSION@#The novel splicing variant c.2355+1G>C of the TSC2 gene probably underlay the TSC in the proband. Above finding has expanded the variant spectrum of TSC2 and provided a basis for preimplantation genetic testing and/or prenatal diagnosis.

Genetic screening and prenatal diagnosis in high-risk families with tuberous sclerosis complex syndrome / 中华医学遗传学杂志

OBJECTIVE@#To carry out genetic testing and prenatal diagnosis for 29 Chinese pedigrees affected with tuberous sclerosis complex (TSC) and assess efficacy of combined next generation sequencing (NGS) and multiple ligation-dependent probe amplification (MLPA) for the diagnosis.@*METHODS@#NGS and MLPA were used in conjunct to detect variants of TSC1 and TSC2 genes among the probands of the pedigrees. Paternity test was carried out to exclude maternal DNA contamination. Prenatal diagnosis was provided to 14 couples based on the discoveries in the probands.@*RESULTS@#Twenty-seven variants were identified in the TSC1 and TSC2 genes among the 29 pedigrees, which yielded a detection rate of 93.1%. Respectively, 5 (18.5%) and 22 (81.5%) variants were identified in the TSC1 and TSC2 genes. Twelve variants were unreported previously. Prenatal diagnosis showed that five fetuses were affected with TSC, whilst the remaining nine were unaffected.@*CONCLUSION@#Above finding has expanded the spectrum of TSC1 and TSC2 gene variants. Combined NGS and MLPA has enabled diagnosis of TSC with efficiency and accuracy.

Analysis of clinical features and genetic variants in a Chinese pedigree affected with tuberous sclerosis / 中华医学遗传学杂志

OBJECTIVE@#To analyze the clinical features of a Chinese pedigree affected with tuberculosis sclerosis and explore its molecular pathogenesis.@*METHODS@#Clinical data of the proband and members of his pedigree were collected. Whole exome sequencing was carried out to detect variants of the TSC1 and TSC2 genes. Candidate variants was verified by Sanger sequencing and bioinformatic analysis.@*RESULTS@#The proband and his mother, who also had mild features of tuberous sclerosis, were found to harbor a novel heterozygous c.4183C>T (p.Q1395X) variant of the TSC2 gene, which was absent in the 4 healthy relatives. Bioinformatic analysis suggested the variant to be likely pathogenic.@*CONCLUSION@#The heterozygous c.4183C>T (p.Q1395X) variant of the TSC2 gene probably underlay the disease in this pedigree. Above finding has expanded the spectrum of TSC2 gene variants. The more severe symptoms in the proband may be attributed to phenotypic heterogeneity of this disease.

Genetic testing and prenatal diagnosis for a pedigree affected with tuberous sclerosis complex / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for Chinese pedigree affected with tuberous sclerosis complex (TSC).@*METHODS@#The proband and his family members were subjected to Sanger sequencing for variants of the TSC1 and TSC2 genes.@*RESULTS@#The proband was found to harbor a c.2837+1dupG splicing variant at a donor site of the TSC2 gene. The same variant was not found among his family members and the fetus during his mother's subsequent pregnancy.@*CONCLUSION@#The c.2837+1dupG splicing variant of the TSC2 gene has probably predisposed to the TSC in this pedigree. Above finding has enriched the spectrum of pathogenic variants associated with this disease.

Genetic analysis of a mosaic case with low proportion mutation of / 浙江大学学报·医学版

OBJECTIVE@#To perform gene mutation analysis in a patient with atypical clinical manifestations of tuberous sclerosis (TSC) for definite diagnosis.@*METHODS@#Peripheral blood DNA was obtained from a patient with clinically suspected TSC and her parents, and all exons and their flanking sequences of @*RESULTS@#A heterozygous nonsense mutation c.1096G>T (p.E366*) was identified in the exon 11 of the @*CONCLUSIONS@#The somatic mosaic mutation c.1096G>T (p.e366*) may be responsible for the phenotype of TSC in this patient. And the drop digital PCR is expected to be a diagnostic method for somatic cells mosaicism.

Long non-coding RNA MALAT1 enhances the apoptosis of cardiomyocytes through autophagy inhibition by regulating TSC2-mTOR signaling

BACKGROUND: Our previous study showed that knockdown of long noncoding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) attenuated myocardial apoptosis in mouse acute myocardial infarction (AMI). This study aims to explore whether MALAT1 enhanced cardiomyocyte apoptosis via autophagy regulation and the underlying mechanisms of MALAT1 regulating autophagy. METHODS: Cardiomyocytes were isolated from neonatal mice and then stimulated with hypoxia/reoxygenation (H/R) injury to mimic AMI. The autophagy level was assessed using GFP-LC3 immunofluorescence and western blot analysis of autophagy-related proteins. RNA pull-down and RNA immunoprecipitation (RIP) was performed to analyze the binding of MALAT1 and EZH2. Chromatin immunoprecipitation (ChIP) assay was performed to analyze the binding of TSC2 promoter and EZH2. The cell apoptosis was evaluated using TUNEL staining and western blot analysis of apoptosis-related proteins. RESULTS: H/R injury increased MALAT1 expression in cardiomyocytes. Furthermore, MALAT1 overexpression inhibited, whereas MALAT1 knockdown enhanced the autophagy of cardiomyocytes. Moreover, MALAT1 overexpression recruited EZH2 to TSC2 promoter regions to elevate H3K27me3 and epigenetically inhibited TSC2 transcription. Importantly, TSC2 overexpression suppressed mTOR signaling and then activated the autophagy. Further results showed that MALAT1 inhibited proliferation and enhanced apoptosis of cardiomyocytes through inhibiting TSC2 and autophagy. CONCLUSION: These findings demonstrate that the increased MALAT1 expression induced by H/R injury enhances cardiomyocyte apoptosis through autophagy inhibition by regulating TSC2-mTOR signaling.