Evidence of Selection for the α-Globin Gene Deletions and Triplications in a Southern Chinese Population.
α(+)-Thalassemia (α(+)-thal) is common in Southern China. The high frequency could be due to over dominant selection through malaria. Two molecular mechanisms that produce α(+)-thal have been defined; one results in the -α(3.7) (rightward) deletion and reciprocal ααα(anti 3.7) triplication, and the other one results in the -α(4.2) (leftward) deletion and reciprocal ααα(anti 4.2) triplication. Considering that each de novo event produced a chromosome with an α gene deletion and a chromosome with an α triplication, if there is no favorable allele, one would expected to find the same allelic frequencies. We found a favorable selection for the -α(3.7) deletion in the Chinese population, and we also found that the α triplication is not as rare as was first thought, especially for the ααα(anti 3.7) triplication.
a Prenatal Diagnostic Center, Guangzhou Women & Children Medical Center affiliated to Guangzhou Medical University , Guangzhou , Guangdong , China.
Xing-Mei
XM
Xie
a Prenatal Diagnostic Center, Guangzhou Women & Children Medical Center affiliated to Guangzhou Medical University , Guangzhou , Guangdong , China.
Man-Yu
MY
Wu
a Prenatal Diagnostic Center, Guangzhou Women & Children Medical Center affiliated to Guangzhou Medical University , Guangzhou , Guangdong , China.
Dong-Zhi
DZ
Li
D044466:Asian People / Q000235:genetics*; D002681:China / Q000453:epidemiology; D017353:Gene Deletion; D020440:Gene Duplication; D005787:Gene Frequency; D006801:Humans; D005810:Multigene Family; D012641:Selection, Genetic; D017384:Sequence Deletion; D055542:alpha-Globins / Q000235:genetics*; D017085:alpha-Thalassemia / Q000453:epidemiology* / Q000235:genetics*
D055542:alpha-Globins
positive selection; single-gene deletions; triplications; α-Thalassemia (α-thal)