Alpha-gene deletions in black newborn infants with Hb Bart's.
The presence of increased Hb Bart's (gamma 4) in cord blood is believed to be an indication of alpha-thalassemia. We have used restriction endonuclease nalyses of DNA to compare the number of alpha-genes with the percentage of Hb Bart's in 6 older children who had Hb Bart's at birth and 17 newborns. Four children with > 2% Hb Bart's had Eco R1 alpha-gene patterns and hematologic data consistent with the presence of two alpha-genes, one per chromosome. Of the remaining 19 children, all of whom had < 2% Hb Bart's, 8 had 3, while 11 had 4 alpha-genes. Three infants with Hb Bart's between 1% or less Hb Bart's. infants with 3 alpha-genes may therefore have elevated or normal levels of Hb Bart's at birth. DNA analysis is the definitive method for the determination of heterozygous alpha-thalassemia syndromes in newborns.
D044383:Black People; D002648:Child; D002675:Child, Preschool; D002872:Chromosome Deletion; D004247:DNA / Q000235:genetics; D004909:Erythrocyte Indices; D005312:Fetal Blood; D005914:Globins / Q000096:biosynthesis; D006455:Hemoglobins, Abnormal; D006801:Humans; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000235:genetics*; D013789:Thalassemia / Q000235:genetics*
D006455:Hemoglobins, Abnormal; D005914:Globins; D004247:DNA