Prevalence of rare chromosomal abnormalities according to epidemiological register of congenital malformations in the Moscow region

Abstract

The prevalence of rare chromosomal abnormalities (CAs) has not yet been reliably determined. This task can be accomplished by registering cases of rare CAs among fetuses, live births and stillborn in population-based registries of congenital malformations that exist in most countries of the world. According to the epidemiological register of the Moscow region for the period from 2011 to 2019, the prevalence rate of rare CA was 0,49 cases per 1000 births, their share in the structure of all CA is 11,3%. In percentage terms, the structure of rare CAs is presented as follows: triploidy - 41.2%, deletions - 23.9%, unbalanced translocations - 10.6%, rare trisomies - 6%, duplications - 5.6%, marker chromosomes - 3.7%, other rare CAs - 9%. Taking into account the international data, we can assume that the obtained prevalence rate of rare CAs is underestimated due to their underreporting and insufficient diagnosis in the studied region, which requires further research.