Hemoglobin variants, hematological parameters and beta-globin gene cluster haplotypes in an isolated Amerindian group from the Orinoco River Delta.
BACKGROUND
Several previous studies reported that the Venezuelan Warao Indians presented unusual genetic characteristics.


OBJECTIVE
The present study checked previous reports of a high frequency of hereditary persistence of fetal hemoglobin (HPFH) and examined other hematological traits.


METHODS
Standard hematology, electrophoresis on cellulose acetate, fetal hemoglobin alkali denaturation, gamma-globin chain, DNA amplification and sequencing, and denaturing gradient gel electrophoresis determinations were performed in 269 individuals living in two localities of the Orinoco River Delta.


RESULTS
Two beta(s) genes, in apparently non-related individuals, were found. HPFH, detected in this same population of Warao Indians 25 years ago, was present in heterozygous form in five individuals from a large kindred, with hemoglobin F levels ranging from 3.7% to 8%, and with a pancellular distribution. The HPFH mutation was of the deletional type. beta-globin gene haplotypes were determined by direct counting (through family studies) in 150 chromosomes; 26% of the 150 examined cluster presented haplotype 2, 22% haplotype 6, and 13% a new, Warao haplotype. Haplotype 3, of probable African origin, was also found with a frequency of 5%.


CONCLUSIONS
The presence of the HPFH mutation was confirmed, and the new beta-globin gene haplotype together with the presence of other rare variants indicates that the Warao are very distinctive in relation to other Native Americans. Evidence was also found of a slight admixture from Africa-derived subjects (Layrisse et al. 1988).
Arends
Anabel
A
Laboratorio de Investigación de Hemoglobinas Anormales, Servicio de Hematología Dr Tulio Arends Hospital Universitario de Caracas, Caracas, Venezuela. aarends@cantv.net
Chacín
Marycarmen
M
Bravo-Urquiola
Martha
M
Tibisay
Arends De O
Ade O
Alvarez
Maritza
M
Castillo
Omar
O
Guevara
Jose M
JM
D000483:Alleles; D044383:Black People / Q000235:genetics; D002648:Child; D002874:Chromosome Mapping; D005260:Female; D005319:Fetal Hemoglobin / Q000032:analysis / Q000235:genetics; D005787:Gene Frequency; D005788:Gene Pool; D005914:Globins / Q000032:analysis / Q000235:genetics*; D006239:Haplotypes; D006455:Hemoglobins, Abnormal / Q000032:analysis* / Q000235:genetics; D006579:Heterozygote; D006801:Humans; D007199:Indians, South American / Q000235:genetics*; D008297:Male; D010375:Pedigree; D044382:Population Groups / Q000235:genetics; D017384:Sequence Deletion; D014687:Venezuela
D006455:Hemoglobins, Abnormal; D005914:Globins; D005319:Fetal Hemoglobin