ABSTRACT
Familial benign polycythemia (FBP) (OMIM 263400) is a rare autosomal recessive condition characterized by erythrocytosis, normal leukocyte and platelet counts, normal uric acid level, and usually increased erythropoietin production. There is a high incidence of this disorder in Chuvashia (Russian Federation), probably due to a founder effect. In an attempt to locate the gene responsible for this disorder, we have carried out linkage studies in 12 Chuvash families, with 35 affected and 32 unaffected members. Linkage to the erythropoietin and erythropoietin receptor loci was excluded, and the FBP gene was assigned to the region of chromosome 11q23 between D11S4142 and D11S1356, with a maximal lod score of 6.61.
Subject(s)
Chromosomes, Human, Pair 11/genetics , Polycythemia/genetics , Chromosome Mapping , DNA/genetics , Family Health , Female , Genotype , Haplotypes , Humans , Male , Microsatellite Repeats , Phenotype , Polycythemia/pathologyABSTRACT
Blood oxygen balance and acid-base equilibrium were studied in 22 Chuvash patients with hereditary erythrocytosis. Despite the lack of the anomalous types of hemoglobin in the given type of erythrocytosis a number of the patients showed secondary tissue hypoxia associated with hyperoxia of the peripheral venous blood. It is shown that tissues are capable of extracting oxygen from the blood. It is assumed that the development of tissue hypoxia in the patients is determined by a fall in the rate of oxygen diffussion from the capillaries to the tissues or by blood shunting via the arteriolo-venular anastomoses because of microcirculatory disorders. The lowering of hematocrit to the level close to normal with the aid of bloodlettings makes oxygen balance return to normal and reduces tissue hypoxia.
