All issues > Volume 33(2); 1990

Original Article

J Korean Pediatr Soc. 1990;33(2):153-161. Published online February 28, 1990.

Cytogenetic Analysis of Chromosomal Abnormalities in Children.

Key Young Song¹, Kwang Man Kim¹, Joon Sik Kim¹, Hong Dae Cha¹, Heung Sik Kim¹, Chin Moo Kang¹

¹Department of Pediatrics, Keimyung University, School of Medicine, Taegu, Korea

Received: June 21, 1989;  Accepted: September 19, 1989.

Abstract

The present report described the cytogenetic findings in 273 cases under the age of 15 years who were suspected as having chromosomal abnormalities clinically. The cytogenetic analysis was conducted at chromosome laboratory of Keimyung University School of Medicne, from September 1982 to June 1987. The following results were obtained. Chromosomal abnormalities were found in 85 (31.3%) of the cases studied. Of 85 cases, 41 cases (85.9%) had numerical abnormalities and 10 cases (14.1%) revealed structural abnormalities. Autosomal abnormalities were found in 71 cases (83.5%) of which Down syndrome was by far the most frequently observed anomaly seen in 58 cases (81.7%). 14 cases (16.5%) had sex chromosomal abnormalities in which Turner syndrome (5 cases) was most frequent. Kleinefelter syndrome was seen in 1 case and Fragile X in 2 cases. Out of 75 cases which were suspected as being Down syndrome clinically, abnormal findings were found in 58 cases (77.3%). The most frequent karyotype found in Down syndrome was 21-trisomy (82.8%) followed by translocation (12.0%) and mosaicism (5.2%). Out of 8 cases clinically suspected Turner syndrome, 4 cases (50%) showed abnormal chromosomes and Kleinefelter syndrome was confirmed in 1 case (100%). Various other clinical conditions such as sexual organ abnormality, hematologic disorder, growth and developmental retardation, mental retardation, multiple minor defects and congenital heart disease had lower proportion of chromosomal abnormalities showing less than 20%. The maternal age of Down syndrome at delivery was between 25~29 years in 50%. A significantly high rate of chromosomal abnormalities was found in a population with clinical abnormalities in comparison to an unselected population. (0.48〜0.55%, reported in other series). Chromosome analysis was very important for the dignosis of clinically suspected autosomal and sex chromosomal abnormalities and also expected more developed karyotyping analysis for the detection of abnormalities for minor groups which showed lower proportion of chromosomal abnor- malities with present method.

Keywords :Chromosomal abnormality, Children