Kn. Yong et al., Thalassemia carrier screening and prenatal diagnosis among the British Columbia (Canada) population of Chinese descent, CLIN GENET, 55(1), 1999, pp. 20-25
Citations number
18
Categorie Soggetti
Research/Laboratory Medicine & Medical Tecnology","Molecular Biology & Genetics
The goal of thalassemia screening is the identification, prior to the conce
ption or birth of an affected child, of couples where both partners an thal
assemia carriers. When both partners are identified as carriers for alpha-
or beta-thalassemia, the risk of having a fetus who is homozygous or compou
nd heterozygous for the abnormal gene is 25%. A study was pet-formed to ide
ntify whether routine screening for thalassemia is indicated for the Chines
e population in British Columbia (BC). In a population of 783 subjects, stu
died either prospectively or retrospectively, 5.0% were alpha-thalassemia c
arriers and 1.7% were beta-thalassemia carriers.
In addition, a review of all BC cases of prenatal diagnosis for thalassemia
over a 6-year period indicated that 26% of couples were identified as alph
a-thalassemia carriers because of a second or third trimester diagnosis of
fetal hydrops, and 17% of couples referred for beta-thalassemia already had
an affected child. The experience with prenatal diagnosis shows that a sig
nificant proportion of at-risk couples are not identified prior to or early
in a pregnancy. The prevalence of carriers for thalassemia would warrant a
program of education and routine screening for this condition in the BC As
ian population.