Portal de Periódicos da CAPES

Identification of hemoglobin G-Philadelphia (α68 Asn→Lys) and homoglonin matsue-oki (α75 Asp→Asn) in a black infant

1982; Elsevier BV; Volume: 707; Issue: 2 Linguagem: Inglês

10.1016/0167-4838(82)90352-1

1878-1454

Yitao Zeng, M. E. Headlee, JohnW. Henson, H. Lam, J. B. Wilson, T. H. J. Huisman,

Neonatal Health and Biochemistry

Two α-chain variants, Hb G-Philadelphia and Hb Matsue-Oki, were present in members of a relatively large black family from South Carolina. The four Hb G-Philadelphia heterozygotes averaged 35.6% Hb G, suggesting the presence of an α-thalassemia-2 condition in cis to the Hb G mutation, which was confirmed by DNA structural analysis. The seven Hb Matsue-Oki heterozygotes averaged 22.2% Hb MO and likely have four active α-chain genes. One infant was a compound heterozygote for the two Hb variants which could not be separated from each other. The quantity of Hb G plus Hb MO was 58% by DEAE-cellulose chromatography and 69% by chain analyses. These results and the family data indicate that this child had three active α-chain genes, of which one regulated the synthesis of the normal a chain, one was mutated to give the αG chain, and one to give the αMO chain. The amino acid substitutions in Hb G-Philadelphia and Hb Matsue-Oki are located in the tryptic peptide αT-9, which is 29 amino acid residues long. Structural analyses of these abnormalities made use of high-pressure liquid chromatography for the separation of both tryptic and thermolytic peptides and of a highly sensitive ultra-micro sequencing procedure. Although the α68 Asn→Lys substitution is readily demonstrable in Hb G-Philadelphia the elucidation of the α75 Asp→Asn replacement in Hb Matsue-Oki was greatly facilitated by the use of these microprocedures.