【摘要】 作者自1989年以来，对220例先天性智能发育不全患儿进行了细胞遗传学研究，结果发现53例具有染色体异常，检出率为24．1％．异常核型共18个种类，涉及15号染色体，既有数目畸变，又有结构畸变，其中以21三体居多（66．0％）146，XX，t（4；14）（P16；q24）枝型为国内首报．对这些异常核型的成因进行分析，认为①与接触致畸因素有关；②由亲代遗传而来；③与母亲高龄有关。本文的研究结果揭示，广泛开展染色体技术，是诊断和预防智能发育不全、实行优生的一项重要措施。更多还原

【Abstract】 Cytogentic studies of 220 children with congenital mental retardatibn were conductedfrom 1989 to 1994. The incidence of chromosomal anomaly was investigated and chromosome analysiswas performed in all the patients. 53(24. 1 % ) of the children showed chromosomal abnormalities. A-mong them, 37 children had Down’s syndrome,including 24 cases of the trisomy type, 8 cases of themosaic type and 5 cases of the translocation type. 3 children had other autos0mal numeral abnormali-ties: 2 cases were trisomy 13 or 18 and 1 case mosaic monosomy 21. 9 patients had other autohomalstructural abnormalities: 46, XY, 5P- . 46, XY (XX), inv (9). 46, XY, t (7;10 ). 46, XY, t (3; 11 ) . 46,XX,t(4 ;14) .46,XX,del(9) ;and karyotype 46,XX,t(4; 14) (p16;q24) which had not been reportedat home previously. 4 children had sex chromosomal abnormalities. The origins of the chromosomal ab-normalities were also discussed.更多还原