Korean J Fertil Steril.  1997 Aug;24(2):199-210.

A Cytogenetic Study of Down's Syndrome

• Moon SY
• Park JS
• Choe J
• Ko HJ
• Oh SK
• Shin CJ

Abstract

A study has been carried out to elucidate the cytogenetic characteristics of Down's syndrome in Korea. This study includes 877 cases which were diagnosed as Down's syndrome by the chromosomal analyses at the Cytogenetic Laboratory, Institute of Reproductive Medicine and Population, Seoul National University for 13 years from January, 1984 to December, 1996. 1. 83.6% of cases were diagnosed under 1 year of age and 10.9% were between 1 and 4 years old. The overall sex ratio was 3 to 2 (male to female). 2. The most frequent indication for cytogenetic analyses was suspicion of Down's syndrome. The next were growth retardation, congenital heart diseases, congenital anomalies. 3. 88.4% of cases had free trisomy 21 In 6.5%, there was translocation, mostly Robertsonian t(14;21) or t(21;21). 3.9% of cases were mosaics mostly with one normal cell line. 4. Karyotyping was also performed in 204 parents of patients. 6 parents (2.9%) were seen to be translocation carriers of Down's syndrome. We find the unique features of Down's syndrome in Korea that the incidences of free trisomy 21 is relatively lower and that translocation is higher than western countries.

MeSH Terms

Cell Line
Child, Preschool
Cytogenetic Analysis
Cytogenetics*
Down Syndrome*
Heart Diseases
Humans
Incidence
Karyotyping
Korea
Parents
Reproductive Medicine
Seoul
Sex Ratio