Prenatal chromosomal microarray analysis in foetuses with isolated absent or hypoplastic nasal bone

Abstract

Objectives To evaluate the efficiency of chromosomal microarray analysis (CMA) in the prenatal diagnosis of foetuses with isolated absent or hypoplastic nasal bone (NB) in the first and second trimester. Methods From January 2015 to April 2021, foetuses with isolated absent or hypoplastic NB who received invasive prenatal diagnosis were enrolled. The results of CMA were analysed Results There were 221 foetuses, including 166 cases with isolated absent NB and 55 cases with isolated hypoplastic NB. Twenty-four foetuses (10.9%, 24/221) had an ultrasonic diagnosis in the first trimester and 197 (89.1%, 197/221) had a ultrasonic diagnosis in the second trimester. The overall diagnostic yield of CMA was 9.0% (20/221). Aneuploidies were detected in 13 (5.9%, 13/221) foetuses, including 10 Down syndrome, 2 Klinefelter's syndrome and 1 trisomy 18. Pathogenic copy number variations (CNVs) were detected in seven foetuses (3.2%, 7/221). In addition, variants of unknown significance (VOUS) were detected in four foetuses. The foetuses with isolated absent NB had a higher detection rate of chromosome abnormality than the isolated hypoplastic NB, but the difference was not significant in the statistical analysis (10.2% vs. 5.5%, χ 2 =0.642, p = .423). No significant difference was observed in the detection rate between the first trimester and the second trimester (16.6% vs. 8.1%, χ 2 = 1.002, p = .317, Chi-square test). Conclusion CMA can increase the diagnostic yield of chromosome abnormality, especially pathogenic CNVs for foetuses with isolated absent or hypoplastic NB. CMA should be recommended when isolated absent or hypoplastic NB is suspected antenatally.7

Chromosomal Microarray Analysis in Fetuses With Ultrasonographic Soft Markers: A Meta-Analysis of the Current Evidence

“…Table 1 summarizes information on the 7 studies included in the current study. 12 13 14 15 16 17 18 Cai et al 12 evaluated the genetic abnormalities of fetuses with CPC using SNP array results. They reported that isolated CPC with normal karyotype was associated with pathogenic CNVs in about 3.9% of cases.…”

Prenatal diagnosis of fetuses with absent/hypoplastic nasal bone in second‐trimester using chromosomal microarray analysis

“…At present, there is a scarcity of research on CMA detection for fetal absent/hypoplastic nasal bone. A previous study conducted by Shi et al (2022) emphasized the importance of applying CMA in diagnosing chromosome abnormalities, particularly pathogenic CNVs, in fetuses presenting with isolated absent or hypoplastic nasal bone. Similar to previous studies (Li et al, 2023; Moczulska et al, 2022), in the present study, a high pCNVs detection rate was observed in the isolated absent/hypoplastic nasal bone group.…”

Absent or hypoplastic nasal bone: What to tell the prospective parents?

“…Numerous studies have proposed a similar methodology (Benacerraf et al, 2019; Desai et al, 2019; Zhang et al, 2021) Adhering to this strategy in low‐resource situations will lower costs and the number of invasive treatments performed. However, when doing invasive testing, the sample should be sent for a more detailed analysis of the genomic structure of the fetus, like the microarray, over the conventional karyotype, as has been outlined in several studies (Fantasia et al, 2020; Gu et al, 2019; Shi et al, 2022; Zhang et al, 2021). In cases where the couple does not want invasive testing, screening with cffDNA can be offered after genetic counseling.…”