[Cytogenetic study of 257 mentally deficient patients in psychiatric hospitals]

Cytogenetic survey of 257 mentally retarded individuals. A cytogenetic inquiry was undertaken among 257 patients with mental retardation of two psychiatric hospitals. 25 patients show chromosomes anomalies (10%). We found: --18 trisomy 21 (Down's syndrome); --3 sexual chromosome anomalies: 47, XYY syndrome; 47, XYY/46, XY mosaïcism; 47, XXY, or Klinefelter syndrom; --1 partial delection of long arm of chromosome number 18 (46, XX, 18 q--); --3 translocations; 45, XX, t (1, 13) (p 36, q 11); 46, XX, t (5 p--, 18 p+) (p 12, p 11); 46, XY, t (9, 19) (q 21, p 18). We also found 9 large Y chromosomes (46, XY q+), 8 cases of variant chromosomes, 1 case with chromosomes associations..., we report a case of masculine Turner phenotype or Noonan syndrom.