Alpha-thalassemia screening reveals quadruple zeta-globin genes in a Laotian family.
In screening families for alpha-thalassemia (thal) by the Southern blot technique, several Laotian families were found which had anomalous zeta-globin haplotypes. The zeta-globin genes encode alpha-like embryonic hemoglobin subunits in the alpha-globin multigene complex on chromosome 16. There are normally two zeta-globin genes in this cluster: 5' zeta 2 and 3' psi zeta 1. In our study, six individuals in three families had triple zeta-globin genes. Another family revealed a novel quadruple zeta-globin arrangement. Two aberrant fragments were seen in Eco R1, Bam H1, Bgl II and Hind III digests using a zeta-globin gene probe. These anomalous bands were in the integral 10 kb range consistent with duplication of the zeta-globin region. This haplotype interpretation was confirmed by Southern blot analyses using double digestions hybridized to a cDNA zeta-gene probe, and Pvu II digests probed with a 5'-psi zeta 1 intergenic fragment. Proposed mechanisms of recombination and implications of this novel arrangement are discussed.
Titus
E A
EA
Department of Genetics, John Burns School of Medicine, University of Hawaii, Honolulu 96822.
Hsia
Y E
YE
Hunt
J A
JA
D015139:Blotting, Southern; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D005914:Globins / Q000235:genetics*; D006239:Haplotypes; D006254:Hawaii; D006801:Humans; D007812:Laos / Q000208:ethnology; D008297:Male; D008403:Mass Screening; D005810:Multigene Family; D010375:Pedigree; D011110:Polymorphism, Genetic; D013789:Thalassemia / Q000235:genetics*
D005914:Globins