Heterogeneity in alpha-thalassemia interactions in Malays, Chinese and Indians in Malaysia.

Abstract

AIM:

Interactions between different determinants of alpha-thalassemia raises considerable problems, particularly during pregnancies where antenatal diagnosis is necessary. This study aims to determine the different types of deletional alpha-thalassemia and Hemoglobin Constant Spring (HbCS), and their frequency in Malays, Chinese and Indians in Malaysia.

METHODS:

DNA from 650 pregnant women from the Antenatal Clinic of the University of Malaya Medical Center in Kuala Lumpur, Malaysia who showed mean cell volume < or =89 fL and/or mean cell hemoglobin < or =28 pg were analyzed for the double alpha-globin gene South-East Asian deletion (--SEA), the -alpha3.7 and -alpha4.2 single alpha-globin gene deletions and HbCS.

RESULTS:

One hundred and three (15.8%) of the pregnant women were confirmed as alpha-thalassemia carriers: 25 (3.8%) were alpha-thalassemia-1 carriers with the --SEA/alphaalpha genotype, 64 (9.8%) were heterozygous for the -alpha3.7 rightward deletion (-alpha3.7/alphaalpha), four (0.6%) were heterozygous for the -alpha4.2 leftward deletion (-alpha4.2/alphaalpha), nine (1.4%) were heterozygous for HbCS (alphaCSalpha/alphaalpha) and one (0.2%) was compound heterozygous with the -alpha3.7/alphaCSalpha genotype. The double alpha-globin gene --SEA deletion was significantly higher in the Chinese (15%) compared to the Malays (2.5%) and not detected in the Indians studied. The -alpha3.7 deletion was distributed equally in the three races. HbCS and -alpha4.2 was observed only in the Malays.

CONCLUSION:

The data obtained gives a better understanding of the interactions of the different alpha-thalassemia determinants in the different ethnic groups, thus enabling more rapid and specific confirmation of alpha-thalassemia in affected pregnancies where antenatal diagnosis is necessary.

• Authors: Yong-Chui Wee, Kim-Lian Tan, Teresa Wai-Ping Chow, Sook-Fan Yap, Jin-Ai Mary Anne Tan
• Journal: The journal of obstetrics and gynaecology research (J Obstet Gynaecol Res) Vol. 31 Issue 6 Pg. 540-6 (Dec 2005) ISSN: 1341-8076 [Print] Australia
• PMID: 16343256 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Globins
• DNA

Topics

• Adolescent
• Adult
• Asian People (genetics)
• Base Sequence
• DNA (genetics)
• Female
• Genetic Carrier Screening
• Globins (genetics)
• Humans
• Malaysia
• Pregnancy
• Pregnancy Complications, Hematologic (diagnosis, genetics)
• alpha-Thalassemia (complications, diagnosis, genetics, prevention & control)