Prenatal diagnosis of monogenic global developmental delay/intellectual disability in 43 pedigrees
10.3760/cma.j.cn113903-20200810-00764
- VernacularTitle:43例单基因全面性生长发育落后/智力障碍家系的产前诊断
- Author:
Liling LIN
;
Ying ZHANG
;
Hairong WU
;
Hong PAN
;
Jingmin WANG
;
Yinan MA
;
Yu QI
- From:
Chinese Journal of Perinatal Medicine
2021;24(1):20-27
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To summarize the prenatal diagnostic characteristics of monogenic global developmental delay/intellectual disability(GDD/ID) pedigrees.Methods:This study retrospectively collected the prenatal molecular diagnostic results of 43 pedigrees that were affected with monogenic GDD/ID in the genetic counseling clinic of Peking University First Hospital from January 2015 to June 2019. The results of prenatal molecular tests were validated after birth or pregnancy termination. Pregnancy outcomes and healthy condition of the offspring were followed up. All data were analyzed by descriptive statistical analysis.Results:Among the 43 pedigrees, 24 were affected with autosomal recessive inheritance (AR) GDD/ID, in which six (25%) fetuses were found to carry two pathogenic variants; 13 (55%) had only one pathogenic variant; five (20%) did not harbor any variant. GDD/ID inherited in an autosomal dominant inheritance (AD) pattern was found in 13 pedigrees, in which 11 fetuses carried no variants while the other two fetuses had the same variants as the proband had (in one pedigree, a low-level variant was detected in the peripheral blood sample of the father while absent in peripheral blood samples of parents in the other pedigree, so it was suspected that the variants of these two affected fetuses were inherited from parental mosaicism). In the other six pedigrees with X-linked inheritance (XL) of GDD/ID, one male fetus was found to harbor the pathogenic variant, while no variants were detected in the others. Maternal contamination was excluded in all prenatal samples using short tandem repeat for linkage analysis. Postnatal validations were consistent with the prenatal tests. All nine affected fetuses were terminated, and the other thirty-four children were delivered and in good health.Conclusions:Prenatal molecular diagnostic test is an effective method to detect pathogenic variants during the first and second trimesters for pedigrees affected by monogenic GDD/ID. For pedigrees affected with AD or XL patterns caused by de novo mutations, potential parental mosaicism should be noted and prenatal diagnostic tests are also recommended.
