Prenatal diagnosis of Wolf-Hirschhorn syndrome characterized by severe fetal growth restriction in three fetuses / 中华围产医学杂志

Objective:To analyze the prenatal clinical characteristics and genetic etiology of Wolf-Hirschhorn syndrome manifested by severe fetal growth restriction (FGR).Methods:Clinical data of three pregnant women admitted to Changsha Hospital for Maternal and Child Health Care from 2018 to 2020 due to severe FGR with or without other malformations diagnosed by prenatal ultrasound were collected. Amniotic fluid samples obtained by ultrasound-guided amniocentesis were analyzed by conventional G-banding staining technique and single nucleotide polymorphism array (SNP array). Parental peripheral blood cells were collected for SNP array to verify the source of variation.Results:(1) The karyotypes of both case 1 and 2 were normal, while case 3 had an abnormal karyotype of 46,XN,der(4)(9pter→9p23::4p15.31→4qter). (2) SNP array indicated a 7.8 Mb microdeletion in 4p16.3p16.1 cytoband in case 1 and a 5.5 Mb microdeletion in 4p16.3p16.2 cytoband in case 2, which were both de novo copy number variations. Case 3 harbored a 19.88 Mb deletion in 4p16.3p15.31 and a 10.89 Mb duplication in 9p24.3p23. (3) All three fetuses were diagnosed as Wolf-Hirschhorn syndrome, and their parents chose to terminate the pregnancies after genetic counseling. Conclusions:Considering the possibility of genetic disease, invasive prenatal diagnosis is suggested when prenatal ultrasonography showed severe FGR, regardless of other malformations, to clarify the cause and guide genetic counseling.

Value of chromosomal microarray analysis for the prenatal diagnosis of pregnancy with high risk signaled by non-invasive prenatal testing / 中华医学遗传学杂志

OBJECTIVE@#To explore the value of chromosomal microarray analysis (CMA) for the diagnosis of fetuses with high risk signaled by non-invasive prenatal testing (NIPT).@*METHODS@#From June 2017 to August 2019, 628 pregnant women with high risk signaled by NIPT underwent invasive prenatal diagnosis. Amniotic fluid or cord blood samples were subjected to chromosomal karyotyping analysis or CMA. Pregnancy outcome and postnatal conditions of the fetuses were followed up.@*RESULTS@#The positive predictive value for trisomy 21, trisomy 18, trisomy 13, sex chromosome aneuploidy, other rare trisomies and copy number variants (CNVs) among the 628 women were 86.4% (127/147), 41.7% (30/72), 12.9% (4/31), 43.7% (101/231), 16.5% (14/85) and 52.2% (35/67), respectively. In 218 samples with normal karyotype, 5.5% (12/218) of additional pathogenic CNVs and 2.3% (5/218) of loss of heterozygosity were detected by CMA.@*CONCLUSION@#CMA combined with karyotyping analysis can be used as first-tier test for prenatal diagnosis for women with high-risk signaled by NIPT.

Diagnosis of a fetus with a de novo 16q partial trisomy syndrome / 中华医学遗传学杂志

OBJECTIVE@#To carry out prenatal diagnosis on a fetus with abnormal findings by ultrasonography and non-invasive prenatal testing.@*METHODS@#The fetus and both parents were subjected to chromosomal karyotyping and single nucleotide polymorphism array (SNP-array) analysis.@*RESULTS@#The karyotypes of both parents were normal. The fetus carried a 46,N,der(X;16)(q28;q22) unbalanced translocation. SNP-array analysis confirmed that the derived chromosomal fragment of the fetus has originated from 16q. The fetus was diagnosed with 16q partial trisomy syndrome.@*CONCLUSION@#Combined chromosomal karyotyping analysis and SNP-array can detect chromosomal aberrations at submicroscopic level and enable accurate diagnosis of the fetus.