Journal of Advanced Medical Research Vol.2 No.2, June 2012, 55-60
A Novel Method for Early Detection
of Down’s Syndrome on Sudanese
Pregnancy
Amin A. E. Elzaki
1,2a
, H. Osman
2
, N.I.Ali
3
,
I.G.Abdulrahman
4
1
Alzaiem Alazhari University, Sudan
2
Taif University KSA
3
Sudan Atomic Energy Commission Sudan
4
Joba University SUDAN
a
Aminzaki2000@yahoo.com
Article Info
Received: 20
th
December 2011
Accepted: 16
th
April 2012
Published online: 1
st
June 2012
ISSN: 2231-8313 © 2012 Design for Scientific Renaissance All rights reserved
ABSTRACT
Based on 1988 cross-sectional data, the lifetime economic costs of Down’s syndrome DS have been
estimated to be $410,000 per case. With a poor Sudanese society, such a like high cost investigations
are not available in Sudanese hospitals. By the other hand, the risk for DS and certain other
chromosome anomalies increases substantially with advancing maternal age. Once again the maternal
age of the Sudanese women is increasing in the last two decades. So that screening test during
pregnancy is becoming highly recommended to avoid such pregnancies. The purpose of the study is to
establish a local reference values for Serum Human Chorionic Gonadotrophin hCG and Alpha
Fetoprotein AFP, in the first trimester of gestation to evaluate the use of these two serum markers as a
method of choice for screening early detection of fetal DS at the same gestational age. A maternal
serum of 176 women was obtained. Samples were taken at the first trimester and both hCG and AFP
were evaluated by score without regard for the maternal age-related DS risk. A sensitive and highly
specific immunoradiometricassay IRMA based on I
125
radiolabeled monoclonal antibody was used for
a quantitative determination of hCG & AFP. Diagnosis was confirmed by ultrasonography U/S in the
second trimester.
Both hCG and AFP and age result showed statistically significant differences between the unaffected
and DS groups, where p-values were (0.001). Multiple of Median MoM of DS for hCG and AFP was
(>3.3 and <0.25) respectively. Local reference values which took from 95 percentile confident
intervals for hCG and AFP have been established, and could replace the European values. With the
current methodology serum markers hCG and AFP can be used further in screening for early detection
of DS on Sudanese pregnant females.
Keywords: Pregnancy, Down’s syndrome, immunoradiometricassay
1. Introduction
DS, Trisomy 21 is a congenital syndrome caused by trisomy of all or part of chromosome
21, is the most common chromosome abnormality. Population-based surveillance programs
have reported a DS birth prevalence of 0.9/1,000 live births (Palomaki et al., 1987). The
incidence of DS is higher than the birth prevalence, however, since many fetuses are
spontaneously aborted, some are recognized in utero and electively aborted, and some cases