Genetic counseling and genetic heterogeneity in the thalassemias.
In this study, we have compared the hemoglobin A2 levels (Hb A2) of alpha-thalassemia carriers (-alpha/-alpha and -alpha/alpha alpha genotypes) with those of double heterozygotes for delta+ and beta thalassemia genes, who were identified by family studies and polymorphic restriction site analysis within the beta-globin gene cluster. We found that double heterozygotes for the delta+ and beta thalassemia have significantly (p less than 0.001) higher Hb A2 levels as compared with carriers of alpha-thalassemia. This finding has practical implications in the genetic counseling of subjects with a thalassemia-like phenotype associated with normal or borderline Hb A2 levels.
Paglietti
E
E
Galanello
R
R
Addis
M
M
Cao
A
A
D004262:DNA Restriction Enzymes; D006580:Genetic Carrier Screening; D005817:Genetic Counseling; D008040:Genetic Linkage; D005838:Genotype; D005914:Globins / Q000235:genetics; D006443:Hemoglobin A2 / Q000032:analysis; D006801:Humans; D010375:Pedigree; D011110:Polymorphism, Genetic; D013789:Thalassemia / Q000235:genetics*
D005914:Globins; D006443:Hemoglobin A2; D004262:DNA Restriction Enzymes