Hemoglobin Sabine Beta 91 (F 7) Leu → Pro

Abstract

Hemoglobin Sabine (α₂β₂ 91 leu → pro) comprises 8 per cent of the hemoglobin of a 16-year-old Scotch-English-German girl who has suffered from hemolytic anemia since infancy. The spleen was removed at 18 months. She has about 9 gm of hemoglobin per 100 ml, of which 12 percent is fetal, and a red-cell count of 2,500,000, with many reticulocytes and erythrocytic inclusions readily demonstrable on fluorescence microscopy. The erythrocyte half-time measured with ⁵¹Cr is four days. Hemoglobin Sabine is deficient in heme-binding capacity, is easily converted to methemoglobin and precipitates readily on mild heating or storage. Replacement of the leucine by a proline residue at β 91 in the helical position F 7 evidently disrupts the helical sequence of the globin molecule at a point adjacent to its chief heme contact. Hemoglobin Sabine probably arose as a mutation in the proposita.