hyperunstable hemoglobin that causes severe hemolytic anemia; has mutation that leads to a deletion of 4 amino acid residues (Leu-Leu-Glu-Asn) at positions 105-108 and an insertion of 9 residues (Val-Pro-Ser-Val-Thr-Leu-Phe-Phe-Asp) at the same location, creating an abnormal elongated beta-chain of 151 amino acid residues
