Frequency of submicroscopic chromosome aberrations in pregnancies without increased risk for structural chromosome aberrations: a systematic review of literature and meta-analysis

4 years ago

Frequency of submicroscopic chromosome aberrations in pregnancies without increased risk for structural chromosome aberrations: a systematic review of literature and meta-analysis

Diane Van Opstal, Marike Polak, Maarten F.C.M. Knapen, Marieke Joosten, Malgorzata I. Srebniak, Stefanie van Veen, Lidia R. Arends, Attie Go

Objective To establish the frequency of pathogenic submicroscopic chromosome aberrations in fetuses that are not at increased risk for unbalanced structural chromosome aberrations, a systematic literature search was performed. The aim was to determine whether high resolution testing for submicroscopic aberrations is beneficial in a general pregnant population. Methods On 3rd June 2016 Embase and PubMed databases were systematically searched for all relevant articles on prevalence of pathogenic submicroscopic CNVs in fetuses tested due to advanced maternal age or parental anxiety. Relevant full text articles were analyzed and based on the extracted data the prevalence of submicroscopic CNVs was calculated. Results Meta-analysis was conducted in a pooled cohort of 10,614 fetuses based on the 10 largest studies (N > 300) of a total of 19 relevant studies. In 0.84%, 95%CI [0.55%, 1.30%] of fetuses a submicroscopic pathogenic aberration was detected prenatally. The onset/penetrance of the submicroscopic findings was studied in 10,314 fetuses out of 8 papers that presented aberrant cases with all necessary details. The pooled estimates resulting from meta-analysis of the data indicated that in 0.37%, 95% CI [0.27%, 0.52%] an early onset syndromic disorder was detected, in 0.30%, 95% CI [0.14%, 0.67%] a susceptibility CNV was found, and in 0.11%, 95% CI [0.05%, 0.21%] cases of late onset diseases were reported. The prevalence of early onset syndromic disorders due to a submicroscopic aberration was calculated to be 1:270. When the risk for submicroscopic aberrations would be added to the individual risk for microscopic chromosome aberrations, all pregnant women have a risk higher than 1:180 for a relevant chromosome aberration, and pregnant women under 36 years old have a higher risk for submicroscopic pathogenic aberrations than for Down syndrome. Conclusion This systematic review shows that a significant proportion of fetuses in a general pregnant population carry a submicroscopic pathogenic CNV. Based on these figures all women should be informed on their individual risk for all pathogenic chromosome aberrations and not only for common trisomies.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/uog.17533