Significance and case analysis of FMR1 mutation screening during early and middle pregnancy / 中华医学遗传学杂志

OBJECTIVE@#To screen for mutations of fragile X mental retardation 1 (FMR1) gene during early and middle pregnancy and provide prenatal diagnosis for those carrying high-risk CGG trinucleotide expansions.@*METHODS@#Peripheral blood samples of 2316 pregnant women at 12 to 21(+6) gestational weeks were collected for the extraction of genomic DNA. CGG repeats of the FMR1 gene were detected by fluorescence PCR and capillary electrophoresis. Genetic counseling and prenatal diagnosis were provided for 3 women carrying the premutations.@*RESULTS@#The carrier rate of CGG repeats of the FMR1 gene was 1 in 178 for the intermediate type and 1 in 772 for the premutation types. The highest frequency allele of CGG was 29 repeats, which accounted for 49.29%, followed by 30 repeats (28.56%) and 36 repeats (8.83%). In case 1, the fetus had a karyotype of 45,X, in addition with premutation type of CGG expansion of the FMR1 gene. Following genetic counseling, the couple chose to terminate the pregnancy through induced labor. The numbers of CGG repeats were respectively 70/- and 29/30 for the husband and wife. In case 2, amniocentesis was performed at 20 weeks of gestation. The number of CGG repeats of the FMR1 gene was 29/-. No abnormality was found in the fetal karyotype and chromosomal copy number variations. The couple chose to continue with the pregnancy. Case 3 refused prenatal diagnosis after genetic counseling and gave birth to a girl at full term, who had a birth weight of 2440 g and no obvious abnormality found during follow-up.@*CONCLUSION@#Pregnant women should be screened for FMR1 gene mutations during early and middle pregnancy, and those with high-risk CGG expansions should undergo prenatal diagnosis, genetic counseling and family study.

Identification of a novel CRYGC mutation in a pedigree affected with congenital cataracts / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a Chinese pedigree affected with congenital cataracts.@*METHODS@#Clinical data and peripheral blood samples were collected for the pedigree. Following extraction of genomic DNA, whole exome sequencing was carried out to detect genetic variants. Candidate variants were verified by familial co-segregation analysis and Sanger sequencing. Bioinformatics analysis was carried out to predict the function of mutant genes.@*RESULTS@#By comparing variants identified among affected and unaffected individuals, a heterozygous variant, c.110 G>C (p.R37P), was identified in exon 2 of the CRYGC gene among all patients, which also matched the criteria for potential disease-causing mutations. The result was confirmed by Sanger sequencing.@*CONCLUSION@#The c.110G>C variant of the CRYGC gene probably underlay the congenital cataracts in this pedigree.

Identification of a novel SLC26A4 mutation in a child with enlarge vestibular aqueduct syndrome / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To analyze mutations of SLC26A4 gene and explore their origins for a patient with enlarge vestibuar aqueduct syndrome.</p><p><b>METHODS</b>Clinical data and peripheral venous blood samples were collected from the patient and her parents. Genome DNA was extracted from the peripheral blood. All of the 21 exons of the SLC26A4 gene were amplified with PCR and subjected to directly sequencing.</p><p><b>RESULTS</b>The patient was found to have carried two mutant alleles of the SLC26A4 gene, namely c.1522A to G and c.1229C to T, which were inherited from her father and mother, respectively.</p><p><b>CONCLUSION</b>SLC26A4 c.1522A to G is likely to be a pathogenic mutation. Above results may facilitate genetic counseling and prenatal diagnosis for this family.</p>

Tetrandrine induces retinoblastoma cells apoptosis via ROS induction and PI3K/Akt inhibition / 中国癌症杂志

Background and purpose:Tetrandrine is a natural compound whose role in retinoblastoma remains unclear. This study investigated the effects of tetrandrine (Tet) on human retinoblastoma cells.Methods:CCK-8 assays were performed to analyze the effects of Tet on viability of retinoblastoma cells. The apoptosis rate was determined by Annexin V/PI assays. After staining with 2′,7′-dichlorolfuorescin diacetate (DCFH-DA), cellular reactive oxygen species (ROS) was measured by lfow cytometry. Akt and p-Akt were detected by Western blot.Results:Tet inhibited cell viability of retinoblastoma cells. After treatment with Tet (4, 8, 10 and 20μmol/L) for 24h, cell viability inhibition rates of WERI-Rb-I were 5.7%, 25.0%, 55.1% and 84.9%, whereas inhibition rates of Y79 cells were 2.4%,2.9%, 23.8% and 54.2% (P<0.01). In cells treated with 10μmol/L of Tet for 12, 24 and 48 h, cell viability inhibition rates of WERI-Rb-I were 6.0%, 45.5% and 74.7%, whereas inhibition rates of Y79 cells were 2.9%, 19.4% and 43.3% (P<0.01). Tet induced retinoblastoma cell apoptosis. After treatment with Tet (10 μmol/L) for 24 and 48 h, apoptosis rates of WERI-Rb-I were (23.70±1.75)% and (34.83±3.15)%, respectively, whereas apoptosis rates of Y79 cells were (9.62±2.69)% and (14.97±1.50)%, respectively (P<0.01). Apoptosis inhibitor Z-VAD-FMK attenuated Tet-induced cell death (P<0.05). ROS levels were indeed increased in cells treated with Tet (10 μmol/L) for 6 and 12 h (P<0.01), while N-Acetyl-L-cysteine (NAC) decreased Tet-induced ROS (P<0.01). After ROS was inhibited by NAC, apoptosis rate was decreased compared with the control (P<0.01). Further study indicated that Tet inhibited PI3K/Akt pathway in retinoblastoma cells.Conclusion:Tet induces cell apoptosis via increasing ROS synthesis and inhibiting PI3K/Akt pathway.