title: Fetal haemoglobin production and the sickle gene in the oases of Eastern Saudi Arabia.
abstract: Fetal haemoglobin (HbF) levels have been measured in 137 normal (AA) subjects, 109 with the sickle-cell trait (AS) and 237 with sickle-cell anaemia (SS) from the oasis population of Eastern Saudi Arabia. In addition the proportion of F-cells has been estimated in 71 AA, 51 AS and 34 SS subjects. The mean HbF% (and the range of F-cells %) were: AA 0.77 (0.3--18), AS 1.38 (2.3--43) and SS 25.56 (33--98). The distribution of Hb F was always heterocellular. The influence of pregnancy accounts for most of the excess female subjects with sickle-cell trait showing raised Hb F and F-cells. Whilst the normal Arabs and those with sickle-cell trait did not differ from comparable groups of American blacks, both the % Hb F and % F-cells in Saudi Arabian patients with sickle-cell anaemia were much higher than in Blacks. The high Hb F levels in individuals with sickle-cell anaemia are not due to coexistent glucose-6-phosphate dehydrogenase deficiency or alpha-thalassaemia trait, and the Hb F level showed an inverse correlation with the degree of haemolysis. These findings indicate that the unusually elevated levels of Hb F are not due to an associated high frequency of a gene for hetero-cellular hereditary persistence of fetal haemoglobin in the oasis population, but rather from a genetically determined absolute increase in Hb F production related in some way to the SS genotype.
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000755:Anemia, Sickle Cell / Q000097:blood* / Q000453:epidemiology / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D005260:Female; D005319:Fetal Hemoglobin / Q000032:analysis*; D005838:Genotype; D006443:Hemoglobin A2 / Q000032:analysis; D006801:Humans; D008297:Male; D011247:Pregnancy; D012529:Saudi Arabia; D012737:Sex Factors; D006113:United Kingdom / Q000208:ethnology
chemical_list: D006443:Hemoglobin A2; D005319:Fetal Hemoglobin