Objective:To investigate the prenatal genetic testing for suspected Beckwith-Wiedemann syndrome (BWS) to improve its prenatal diagnosis rate.Methods:This study reported a pregnant woman, who had a pregnant history of termination due to the same reason at 18 weeks, with fetal acromphalus and unusually thickened placenta indicated by ultrasound examination at 13 weeks of gestation. After chorionic villus sampling, single nucleotide polymorphism (SNP) array was used to analyze copy number variations in the whole genome, and methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) was also performed to detect the methylation and copy number variations in H19 and KCNQ1 genes on chromosome 11p15. Peripheral blood samples were collected from the couple for chromosome G-banding karyotype analysis and SNP array. Results:The SNP array indicated a 176 kb heterozygous deletion in the 11p15.5 region. MS-MLPA revealed a loss of methylation at imprinting control region 2 and a 50% reduction of copy numbers of KCNQ1 (L02903) gene. No abnormality was found in the parents in the SNP array and G-banding karyotype analysis. The fetus was prenatally diagnosed with BWS. Conclusions:When intrauterine abnormalities, such as acromphalus and abnormal thickening of the placenta, are found by ultrasound during early pregnancy, prenatal genetic tests related to BWS, including MS-MLPA and SNP array, are suggested to avoid a missed diagnosis of BWS.

Objective To analyze the fetus chromosome abnormalities in women with advanced maternal age under the universal two-child policy. Methods A total of 10607 women underwent prenatal diagnosis proce-dures from the year of 2015 to 2016,among which 3569 cases were with advanced maternal age. Cytogenetic karyotyping was conducted with chromosomal microarray analysis(CMA)in 854 cases. The ration of chromosome abnormalities in the two population groups(aged from 35~39 and over 40)were counted. The type of abnormali-ties were also analyzed. Results The ration of women with advanced maternal age in 10607 cases underwent pre-natal diagnosis between 2015 and 2016 was 33.6%. The respective rations were 27.2%and 37.9%. The detection rates of chromosome abnormalities were 7.9% and 10.8%,with significantly difference. The significant differences were also found in the detection rate of chromosome aneuploidies ,but no differences in other chromosome abnor- malities. CMA was benefit to detect the micro chromosome abnormalities. Conclusions In 2016,the number of prenatal diagnosis procedures increased under the two-child policy. The detection rate of chromosome abnormalities also significantly increased. The incidence of chromosome abnormalities was higher with the growing age of preg-nant women. Genetic counseling must be presented and prenatal diagnosis should be promoted in women with ad-vanced age.

[Objective] To describe a case of a rare,novel mutation causing recurrent chorioamniotic membrane separation in a Chinese family with combined next-generation sequencing (NGS) and Sanger sequencing.[Methods] For the affected fetus,potential mutation were detected by the conbinedcombined next-generation sequencing (NGS) and Sanger sequencing.And the prenatal diagnosis were identified by Sanger sequencing.[Results] A frameshifting mutation c.1389_1390delAG (inherited from mother),and a missense mutationc.1006 G ＞ C (inherited from mother) have been identified in the affected fetus (the second pregnancy).The prenatal diagnosis of the third fetus turns out to be a carrier,the mutation was inherited from father.[Conclusions] We describe a novel mutation in gene ZMPSTE24,which was considered with mandibuloacral dysplasia with type B,and that may be the cousecoursecausing of recurrent chorioamniotic membrane separation.This rare mutation constitutes an additional heterogeneous defect causing chorioamniotic membrane separation.And the conbinedcombined next-generation sequencing (NGS) and Sanger sequencing allows high resolution characterization of novel mutions that are not readily detected by present methods.