All issues > Volume 40(8); 1997

Case Report

J Korean Pediatr Soc. 1997;40(8):1156-1161. Published online August 15, 1997.

A Case of Unusual (1q;21q) Translocation Down Syndrome Inherited from a t(1q;21q) Balanced Carrier Mother

Dong Hoon DH Yi¹, Jae Ock JO Park¹, Sang Mann SM Shin¹, You Kyoung YK Lee², Won Bae WB Kim², Won Bae WB Lee³, Sung Sup SS Park⁴, Han-Ik HI Cho⁴

¹Department of Pediatrics, College of Medicine, Soonchunhyang University, Seoul, Korea
²Department of Clinical Pathology, College of Medicine, Soonchunhyang University, Seoul, Korea
³Department of Pediatrics, College of Medicine, Catholic University, Seoul, Korea
⁴Departmennt of Clinical Pathology, College of Medicine, Seoul National University, Seoul, Korea

Abstract

Down syndrome is the most common autosomal syndrome in man. The incidence of trisomy 21 due to translocation is about 3.5-5%. Translocations are usually centric fusions between a 21 and a D group (54.2%) or a G group (40.9%) chromosome. Since the short arm of 21 carries no phenotypically active genes, even if the short arm of 21 is lost, usually there is no imbalance with clinical significance. Rare translocations in Down syndrome may also occur between a 21 and other chromosomes (4.9%). We experienced a case of unusual (1q;21q) translocation Down syndrome inherited from a t(1q;21q) balanced carrier mother. The segmental trisomy was confirmed by FISH analysis. This is the first case of a familial Down syndrome with t(1q;21q) in Korea.

Keywords :Down syndrome, Familial, Translocation, FISH