Cytogenetic Evaluation of Down Syndrome : A Review of 1020 Referral Cases

Chandra, N and Cyril, Cyrus and Lakshminarayana, Prema and Nallasivam, P and Ramesh, A and Gopinath, PM and Marimuthu, KM (2010) Cytogenetic Evaluation of Down Syndrome : A Review of 1020 Referral Cases. International Journal of Human Genetics , 10 (1-3). pp. 87-93.

[img] PDF
7_-_Int_J_Hum_Genet_2010-10,__87-93.pdf - Published Version
Restricted to Registered users only

Download (76kB) | Request a copy


A retrospective analysis was performed on 1102 cases with a provisional diagnosis of Down syndrome referred to the Department odf Genetics , Dr. ALMPGIBMS , University of Madras during the period from 1979 to 2006. Cytogenetics analyses confirmed the diagnosis in 1020 cases (92.6 %) . Among them, regular (free) trisomy 21 constituted 83.82 percent. Mosaicism was recordedin 10.78% and Robertsonian trasocations in five percent of cases . The translocation was of de novo origin in about 50 percent of the individuals where families had been investigated . Trisomy 21 was associated with stuctural and numerical chromosmal anomalies in one case each.A tandem 21;21 rearrengement and a familial 13;21 Robertsonian translocation with mosaicism for Y chromosome were seen in two other cases. The mean meternal age was higher in regular trisomy 21 (25.08 years ) than in transolation (22.83 years) cases. An excess of males was seen in all groups expect in the translocation group where the male : female ratio was 0.93. This paper summarizes the chromosomal abnormalities and the clinical features seen in these patients

Item Type: Article
Uncontrolled Keywords: Down Syndrome . Trisomy 21 . Robertsoniam Translocation . Mosaicism. Tandem 21:21 Rearrangement
Subjects: Life Sciences > MLSC Manipal
Depositing User: KMC Manipal
Date Deposited: 31 Jan 2012 07:02
Last Modified: 31 Jan 2012 07:02

Actions (login required)

View Item View Item