title: Homozygosity for the delta-chain variant haemoglobin A2' (HbB2) (delta 16 Gly----Arg).
abstract: A healthy 20-year-old woman, belonging to the Kgalagadi tribe of Botswana, has been found to possess a variant Haemoglobin A2 as her only minor haemoglobin component. Fingerprinting and amino-acid analysis have shown that it is Haemoglobin A2' (delta 16 Gly----Arg). The one parent available for study is heterozygous for the Hb delta A2' allele and the variant haemoglobin accounts for 3% of the total haemoglobin in the proband. It is reasoned that the proband is, therefore, homozygous for the Hb delta A2' allele. No haematological abnormalities were evident.
mesh_terms: D000328:Adult; D000596:Amino Acids / Q000032:analysis; D001120:Arginine; D001902:Botswana; D005260:Female; D014644:Genetic Variation; D005998:Glycine; D006441:Hemoglobin A / Q000235:genetics*; D006443:Hemoglobin A2 / Q000235:genetics* / Q000302:isolation & purification; D006720:Homozygote; D006801:Humans; D046911:Macromolecular Substances; D010446:Peptide Fragments / Q000032:analysis; D014357:Trypsin
chemical_list: D000596:Amino Acids; D046911:Macromolecular Substances; D010446:Peptide Fragments; D006441:Hemoglobin A; C049102:hemoglobin A2'; D006443:Hemoglobin A2; D001120:Arginine; D014357:Trypsin; D005998:Glycine