Prenatal diagnosis of suspected recurrent Beckwith-Wiedemann syndrome: a case report and literature review / 中华围产医学杂志

ABSTRACT

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.