title: Identification of a highly polymorphic marker within intron 7 of the ALAS2 gene and suggestion of at least two loci for X-linked sideroblastic anemia.
abstract: We have identified a compound dinucleotide repeat within intron 7 of the human erythroid 5-aminolevulinate synthase (ALAS2) gene with a minimum of 9 alleles and heterozygosity of 78%. ALAS2 was placed on the multipoint linkage map of the X chromosome in the pericentromeric region with the locus order: pter-(DXS255, TFE3, DXS146)-(DXS14, ALAS2, DXZ1)-AR-(DXS153, DXS159)-qter. No recombination was observed between ALAS2 and the centromere marker DXZ1. As ALAS2 has recently been shown to be the defective locus in X-linked pyridoxine-responsive sideroblastic anemia (PRSA), the ALAS2 marker has allowed placement of the gene for PRSA into the multipoint linkage map of the X chromosome. With the previous exclusion of close linkage between DXS14 and sideroblastic anemia with ataxia, our data show that there are at least two loci for X-linked sideroblastic anemia.
authors.affiliation: Department of Biochemistry, University of Adelaide, Australia.
authors.forename: T C
authors.initials: TC
authors.lastname: Cox
authors.forename: H M
authors.initials: HM
authors.lastname: Kozman
authors.forename: W H
authors.initials: WH
authors.lastname: Raskind
authors.forename: B K
authors.initials: BK
authors.lastname: May
authors.forename: J C
authors.initials: JC
authors.lastname: Mulley
mesh_terms: D000624:5-Aminolevulinate Synthetase / Q000235:genetics*; D000756:Anemia, Sideroblastic / Q000235:genetics*; D001483:Base Sequence; D004277:DNA, Single-Stranded; D005260:Female; D008040:Genetic Linkage; D005819:Genetic Markers; D006801:Humans; D007438:Introns; D008297:Male; D008969:Molecular Sequence Data; D010375:Pedigree; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D014960:X Chromosome
chemical_list: D004277:DNA, Single-Stranded; D005819:Genetic Markers; D000624:5-Aminolevulinate Synthetase