Prevalence and molecular heterogeneity of alfa+ thalassemia in two tribal populations from Andhra Pradesh, India.
We describe here the screening of a small group of apparently healthy individuals belonging to the tribal communities of Koya Dora and Konda Reddi. A remarkably high incidence of deletion and nondeletion alpha + thalassemia mutants has been found with allele frequencies and distributions characteristic to each tribe. We have confirmed the strict relationship between Hb S levels and the number of alpha globin genes in double heterozygotes for the S gene and alpha thalassemia. In this population sample we did not find either heterozygous carriers of alpha 0 thalassemia (deletion of both alpha genes in "cis") or individuals showing hemolytic anemia due to inactivation of three alpha-globin genes (Hb H disease). Selection by malaria is most probably responsible for the prevalence of the various alpha + thalassemia haplotypes among the two tribal populations of Andhra Pradesh.
Fodde
R
R
Department of Human Genetics, Sylvius Laboratoria, University of Leiden, The Netherlands.
Losekoot
M
M
van den Broek
M H
MH
Oldenburg
M
M
Rashida
N
N
Schreuder
A
A
Wijnen
J T
JT
Giordano
P C
PC
Nayudu
N V
NV
Khan
P M
PM
D005006:Ethnicity; D005914:Globins / Q000235:genetics*; D006239:Haplotypes; D006451:Hemoglobin, Sickle / Q000235:genetics; D006579:Heterozygote; D006801:Humans; D007194:India; D015183:Restriction Mapping; D012805:Sickle Cell Trait / Q000453:epidemiology / Q000235:genetics; D013789:Thalassemia / Q000453:epidemiology / Q000235:genetics*
D006451:Hemoglobin, Sickle; D005914:Globins