Prenatal diagnosis of beta-thalassemia in the West Bank and Gaza

• Published in: Saudi medical journal Vol. 26; no. 11; p. 1771
• Main Authors: Ayesh, Suhail K, Al-Sharef, Wasif A, Nassar, Suheir M, Thawabteh, Nabeel A, Abu-Libdeh, Bassam Y
• Format: Journal Article
• Language: English
• Published: Saudi Arabia 01-11-2005
• Subjects: Alleles; beta-Thalassemia - diagnosis; beta-Thalassemia - epidemiology; beta-Thalassemia - genetics; Cohort Studies; Developing Countries; DNA Mutational Analysis; Female; Genetic Predisposition to Disease - epidemiology; Genetic Testing; Humans; Incidence; Middle East - epidemiology; Pedigree; Polymerase Chain Reaction - methods; Pregnancy; Prenatal Diagnosis - methods; Retrospective Studies; Risk Assessment; Sex Distribution; Middle East
• ISSN: 0379-5284

This study focuses on the genetic aspect of beta-thalassemia among 88 at risk couples from the West Bank and Gaza, and the attitude of these couples toward prenatal diagnosis and its outcome as a preventive method.
We tested 130 prenatal samples for beta-thalassemia during the period from January 1999 to July 2005. We performed prenatal diagnosis in these cases using the amplification refractory mutation system, as well as beta-globin gene sequencing as a conformational method. We drew a chorionic villus sample (CVS) for 1st trimester pregnant women and amniotic fluid (AF) for those in the 2nd trimester depending on the stage the pregnant woman contacted our lab.
The DNA analysis of 130 prenatal samples revealed 25 (19.2%) cases of beta-thalassemia major and 67 (51.5%) cases of beta-thalassemia carriers, while the remaining 38 (29.2%) were normal. The 25 affected fetuses were aborted according to the wishes of the parents. In the tested 88 couples, 14 mutations of beta-thalassemia were identified. These mutations and their frequencies were: IVSI-110 (22.2%), IVSI-6 (13.6%), Cd37 (12%), IVSI-I (9.7%), IVSII-1 (6.2%), Cd39 (9%), Cd6 (sickle cell mutation) (8.5%), Cd5 (8%), Cd8/9 (2.8%), Cd106/107 (2.8%), -30 promoter (1.1%), -88 promoter (1.1%), IVSI (-1) (2.3%) and IVSI-5 (0.6%). We found that in 77.3% of the couples, both the mother and the father carry the same type of mutation while 22.7% of them carry different mutations. We found 77.9% consanguinity among the couples
We found very good acceptability for prenatal diagnosis in beta-thalassemia afflicted families. All couples with affected fetuses opted for abortion. The spectrum of mutations in the tested couples revealed several similarities to neighboring countries with -88 promoter mutation reported for the first time in our region.