[A cytogenetic study of the functions of the variable regions in human C heterochromatin. II. C heterochromatin in families with hereditary short stature].

The C heterochromatin in chromosomes 1, 9, 16, and Y was studied for 12 families of patients with inherited short stature. A comparison of the results of cytogenetic and genealogical analysis has revealed a correlation between the growth retardation in children and the short stature in parents, and the accumulation of the small C segment in chromosomes 1, 9, and 16 in their karyotypes. These data are entirely consistent with our results obtained for the families having children with gene syndromes (Russell-Silver, Dubowitz etc.) and obligate growth retardation. Obviously, there is a type of narrow height in man associated with the presence of a small amount of C heterochromatin. This appears to be an additional proof of a great importance of C heterochromatin in embryonal and postnatal development. Differential diagnostics of such a type of short stature is important for children endocrinology, since the hormonal growth-stimulated therapy does not have a desirable effect on these patients.