Prenatal diagnosis of Cri-du-chat syndrome: analysis of 11 cases / 中华围产医学杂志

ABSTRACT

Objective:To investigate the ultrasonographic and genetic features of Cri-du-chat syndrome (CDCS).Methods:In this retrospective study, cases with CDCS diagnosed in Wuxi Maternal and Child Health Care Hospital from 2004 to 2021 and with complete data were reviewed to describe and analyze the maternal serum prenatal screening, non-invasive prenatal testing (NIPT), ultrasound, genetic examination data, and pregnancy outcomes.Results:All cases were diagnosed by karyotype analysis, seven of them were diagnosed prenatally through amniotic fluid, and four were diagnosed after birth through peripheral blood. Five of the seven cases diagnosed prenatally had an abnormal serological screening, including two cases with 5p- indicated by NIPT. Of the 11 cases, prenatal ultrasonography showed cerebellar transverse diameter less than －2 SD in eight cases, including four with cerebellar hypoplasia (CH), two with fetal growth restriction, and two with cranial diameters less than －2 SD. One case was shown with an increased nuchal translucency, accompanying bilateral choroid plexus cysts of the lateral ventricles, and suspected persistent left superior vena cava. No obvious ultrasound abnormality was observed in the remaining two cases. Among the seven cases diagnosed prenatally, excluding one case that refused parental verification, further single nucleotide polymorphism array (SNP array) showed that all six cases inherited the de novo mutations from the parents. The cytogenetic analysis found the breakpoints at 5p13, 5p14, and 5p15 in five, three, and three cases. All seven pregnancies were terminated in the second trimester. Four children diagnosed postnatally presented with CDCS phenotype during the follow-up at three years old. Conclusions:Fetal CDCS should be considered with CH detected by prenatal ultrasonography, though the correlation between CH and CDCS still needs further investigation. Gene mapping with an SNP array is helpful for phenotypic profiling and genetic counseling.