Point mutation in the beta-spectrin gene associated with alpha I/74 hereditary elliptocytosis. Implications for the mechanism of spectrin dimer self-association.
AUTOR(ES)
Tse, W T
RESUMO
alpha I/74 hereditary elliptocytosis (HE) is a subgroup of HE in which patients exhibit an impaired self-association of spectrin dimers and an abnormal proteolytic cleavage of the alpha I domain of spectrin. We studied a family in which the proband presented with a severe neonatal hemolytic anemia with poikilocytosis. Biochemical analysis of erythrocytes from the proband and his family members allowed us to ascertain a diagnosis of homozygosity for alpha I/74 HE in the proband and heterozygosity in his parents and several of their offspring. Results of polymorphism linkage analysis suggested that the defect in this family was located in beta rather than alpha spectrin. We analyzed the 3' end of the beta-spectrin gene of the proband and detected a mutation that changes a codon for alanine to one for proline. Allele-specific oligomer hybridization on slot blots of DNA from other family members confirmed the presence of the mutation only in members heterozygous for the disorder. This is the first example of a point mutation in the beta-spectrin chain that is associated with defective spectrin dimer self-association and an abnormal proteolytic cleavage of the alpha chain. Based on this finding, we propose a model for the mechanism of interaction between the alpha- and beta-spectrin chains.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=296810Documentos Relacionados
- A molecular defect of spectrin in a subset of patients with hereditary elliptocytosis. Alterations in the alpha-subunit domain involved in spectrin self-association.
- Defective spectrin dimer-dimer association with hereditary elliptocytosis.
- Four different mutations in codon 28 of alpha spectrin are associated with structurally and functionally abnormal spectrin alpha I/74 in hereditary elliptocytosis.
- Spectrin beta-chain variant associated with hereditary elliptocytosis.
- A novel mobile element inserted in the alpha spectrin gene: spectrin dayton. A truncated alpha spectrin associated with hereditary elliptocytosis.