Characterization of β-globin haplotypes using blood spots from a population-based cohort of newborns with homozygous HbS

Abstract

Purpose: A population-based cohort from three state newborn screening programs was used to describe ␤-globin gene cluster variation. Methods: Blood spots from newborns homozygous for HbS were genotyped for five restriction fragment length polymorphisms (RFLPs) to construct ␤-globin haplotypes. Haplotype distributions were compared by race/ethnicity and sex. Expected heterozygosities were calculated and compared with observed heterozygosities. Results: Haplotype distributions did not differ between sexes for either blacks or Hispanics.Neither racial/ethnic group deviated from Hardy-Weinberg equilibrium; however, Hispanics had higher heterozygosity at two RFLPs compared with blacks. Conclusion: The differences between populations probably reflect recent migration and admixture rather than selection. Genet Med 2002:4(5):328 -335.

Sickle cell in sickle cell disease in Latin America and the United States

“…Older studies described the origins of the sickle cell gene through specific molecular patterns of b-globin sickle gene markers, or haplotypes [31][32][33]. The distribution of these haplotypes from Latinos with SCD originating in the U.S., Brazil, Panama, and Venezuela provide molecular data to support the African origin of the sickle gene, and demonstrate similar distributions of African regions/ethnicities of origin between sample populations tested [34][35][36][37].…”

Hydroxyurea Use in Young Children With Sickle Cell Anemia in New York State

“…Demographics were typical of the sickle cell population in NYS, with a slightly higher proportion of black or African American members than previously reported, which likely reflects differences in reporting of race and ethnicity in Medicaid compared with the sources used for the previous studies. [24][25][26] Linking NBS results directly to Medicaid allowed genotype-specific analyses. A further strength of this study is that it compared rates of initiation and persistence of HU therapy across NYS geographic regions and among providing centers.…”

Fetal Hemoglobin Levels in African American and Hispanic Children With Sickle Cell Disease at Baseline and in Response to Hydroxyurea

“…This frequency was the same as previously reported in New York State from population-based sickle cell samples. 11 All four heterozygotes were AA males, with only one in the hydroxyurea group. For the BCL11A SNP, 13 were heterozygote for the polymorphism associated with a higher baseline HbF: five African American, five Hispanic and two mixed.…”

“…11 Population-based RFLP analysis of newborn screening samples from children with SCD in NY State demonstrated similar distribution of African beta globin gene alleles in Hispanics and African Americans. 11 To date, no report has compared HbF response to hydroxyurea in African American and Hispanic children with SCD.…”