[Anomalies in the karyotypes of premature children].

A cytogenetic investigation of two groups of prematurely born babies was carried out on the basis of the specialized department for prematurely born children in Moscow and in the Moscow Region. The material for this investigation was the culture of lymphocytes. In the first group comprising 607 prematurely born babies without any perceptible developmental defects abnormalities of the karyotype were observed in 15 probands (2.5%) which is 3.5 times higher than the frequency of karyotypic abnormalities among newborn babies from the same population born in proper time. In the second group comprising 70 prematurely born babies with various congenital malformations various karyotypic abnormalities were observed in 13 probands (18,6%), which is 8 times the frequency among babies from the same population born in proper time. The main type of abnormalities observed were those affecting the system of sex chromosomes and the cases of trisomy of the 21st pair of autosomes and structural abnormalities. The high proportion of X- and 21-trisomies among the chromosome abnormalities observed suggests their important role in the etiology of premature births and postnatal death-rate of mutant organisms having D- and E-trisomies and structurally unbalanced chromosomal aberrations.