Use of high-throughput targeted exome sequencing in genetic diagnosis of Chinese family with congenital cataract

AIM： To identify disease-causing mutation in a congenital cataract family using enrichment of targeted genes combined with next-generation sequencing.· METHODS： A total of 371 known genes related to inherited eye diseases of the proband was selected and captured, followed by high-throughput sequencing. The sequencing data were analyzed by established bioinformatics pipeline. Validation was performed by Sanger sequencing.·RESULTS： A recurrent heterozygous non-synonymous mutation c.130 G A（p.V44M） in the GJA3 gene was identified in the proband. The result was confirmed by Sanger sequencing. The mutation showed co-segregation with the disease phenotype in the family but was not detected in unaffected controls.·CONCLUSION： Targeted exome sequencing is a rapid,high-throughput and cost-efficient method for screening known genes and could be applied to the routine gene diagnosis of congenital cataract.

Outcomes of Preimplantation Genetic Diagnosis Cycles by Fluorescent In situ Hybridization of Infertile Males with Nonmosaic 47,XYY Syndrome

Background： The 47,XYY syndrome could result in fertility problems. However, seldom studies reported comprehensive researches on the embryonic development and pregnancy outcomes of these patients. This study aimed to evaluate the clinical outcomes of nonmosaic 47,XYY patients performed with fluorescent in situ hybridization （FISH） and preimplantation genetic diagnosis （PGD） treatment. Methods： This was a retrospective study. Between January 2012 and May 2017, 51 infertile males with nonmosaic 47,XYY syndrome underwent FISH-PGD were included in the study. According to sex chromosomal FISH results, embryos were classified as normal signal, no nuclei fixed, no signal in fixed nuclei, suspensive signal, and abnormal signal groups, respectively. The incidence of each group, the fixation rate, and hybridization rate were calculated. Embryonic development and pregnancy outcomes were also analyzed. The measurement data were analyzed with Student＇s t-test. The comparison of categorical data was analyzed with the Chi-square test and Fisher＇s exact test when expected cell count was 〈5. Results： The 53 PGD cycles with 433 embryos were analyzed. The fixation rate was 89.6%, while the hybridization rate was 96.4%. There were 283 embryos with two sex chromosomal signals with clear diagnosis （65.4%）. The numbers of no nuclei fixed, no signal in fixed nuclei, suspensive signal, and abnormal signal groups were 45 （10.4%）, 14 （3.2%）, 24 （5.5%）, and 67 （15.5%）, respectively. Embryos with abnormal signals were abandoned. The number of good-quality embryos was 210 （57.4%）, including implanted embryos on day 4/day 5 a.ld cryopreserved. The rates of good-quality embryos in the no nuclei fixed （22.2%）, no signal in fixed nuclei （28.6%）, and suspensive signal groups （33.3%） were comparable （P 〉 0.05）, and were significantly lower than the normal signal group （66.4%, P 〈 0.001 ）. The clinical pregnancy rates of fresh and frozen embryos transferred cycles were 70.6% and 85.7%, respectively. Conclusions： Among embryos with a clear diagnosis of sex chromosome, about one-fifth showed abnormal signals. Embryos with two sex chromosomal signals are more likely to develop into good-quality ones. The application of the PGD by FISH may help to improve the clinical outcomes.