title: An intron nucleotide sequence variant in a cloned beta +-thalassaemia globin gene.
abstract: A 7.5 kb Hsu I restriction fragment of genomic DNA containing a beta-globin gene has been isolated from a patient doubly heterozygous for beta + thalassaemia and a delta beta (Lepore globin fusion gene. This fragment must be derived from the chromosome carrying the beta +-thalassaemia determinant. The gross structure of the cloned gene plus flanking sequences is indistinguishable from that of a normal beta-globin gene. Within in 1606 base-pair transcribed region of the gene there is only one nucleotide difference from the normal beta-globin gene sequence. This is a G leads to A replacement 21 nucleotides upstream from the 3' terminus of the small intron. This nucleotide lies within a 10 base-pair sequence repeated in an inverted configuration near the 5' terminus of the small intron. The nucleotide replacement may result in a precursor mRNA less amenable to RNA splicing than its normal counterpart.
mesh_terms: D000328:Adult; D001483:Base Sequence; D003001:Cloning, Molecular; D003090:Coliphages / Q000235:genetics; D004262:DNA Restriction Enzymes; D004274:DNA, Recombinant; D004926:Escherichia coli / Q000235:genetics; D005796:Genes; D014644:Genetic Variation; D005914:Globins / Q000235:genetics*; D006579:Heterozygote; D006801:Humans; D008297:Male; D010957:Plasmids; D013789:Thalassemia / Q000235:genetics*
chemical_list: D004274:DNA, Recombinant; D005914:Globins; D004262:DNA Restriction Enzymes