All issues > Volume 26(3); 1983

Original Article

J Korean Pediatr Soc. 1983;26(3):220-227. Published online March 31, 1983.

Statistical Assessment on Chromosomal Aberrations Observed in Childhood.

Jong Jin Seo¹, Hyung Ro Moon¹

¹Department of Pediatrics, college of medicine, Seoul, National University,Korea.

Abstract

A statistical assessment was carried out in two hundreds and eighty three inpatients and outpatients and fifteen mothers who were subjected to chromosomal analysis at Department of Pediatrics, Seoul National University Hospital, from January 1977 to February 1982. The following results were obtained: 1) Age distribution revealed 65.8% of all children subjected to chromosomal analysis to be: under 2 years of age. The number of children decreased as the age of subjects gets older. 2) Sex distribution revealed boy to girl ratio to be 1.1 : 1. 3) Various types of chromosomal anomalies were encountered in 150 (50.3%) among 298cases. Down syndrome was the leading clinical indication for chromosomalal anysis. 114(80.1%) among 141 cases suspected for Down syndrome revealed chromosomal aberrations compatible with clinical impression except for three subjects. The next most frequent clinical condition for chromosomal study was Turner syndrome. The accuracy of clinical impression for Turner syndrome was 34.4%； for Klinefelter syndrome, the concordance rate was 75.0%. In children with congenital multiple minor defects, growth & mental retardation, and sexual abnormalities, karyotypic abnormalities were found in. 17.6%, 12.5% and 10.0%, respectively. Chronic granulocytic leukemia was the leading category of chromosomal analysis among hematologic disorders revealing Ph1 chromosome in two cases among ten children. Significant chromosomal breakages were found in two cases among three patients with Fanconi` s anemia. Chromosomal aberration was not detected among all the cases studied for mental retardatioiv unaccompanied by other anomalies or isolated congenital heart disease. Fifteen mothers of offspring with Down syndrome were studied for carrier detection and one of them revealed D/G translocation. 4) Autosomal aberrations were found in 128 cases (45.2%) among 283 children studied. Down syndrome was the most frequently observed autosomal aberration numbering 114 cases (40.3%), It was followed by Cri du Chat syndrome which was confirmed in 4 cases(1.4%). 5) The most frequent karyotype revealed in Down syndrome was 21 trisomy(91.2%), followed by translocation (6.2%) and mosaicism (2.6%). 6) Sex chromosomal aberrations were found in 18 cases (6.4%) among 283 children studied. Turner syndrome and Klinefelter syndrome was found in 13 cases (4.6%) and 3 cases (1.1%), respectively. 7) Among the 15 mothers suspected for the balanced carrier of Down syndrome, 14 mothers were under 35 years of age and translocation chromosome was found in one mother aged twenty eight.

Keywords :Chromosomal Aberration; childhood; Statistical Assessment.