title: A novel alpha-globin gene arrangement in man.
abstract: The human genome has two linked alpha-globin genes on chromosome 16. Deletion of one or more of them, as occurs in alpha-thalassaemia, leads to a reduced output of alpha-globin mRNA in proportion to the number of alpha-globin genes lost. In some racial groups deletion of one of the pair of alpha-globin genes may result from unequal crossing over between the genes on homologous chromosomes by a mechanism resembling that postulated for the formation of the delta beta fusion genes of the Lepore haemoglobins. By analogy, the opposite chromosome in this cross-over should have three alpha-globin genes just as the 'anti-Lepore chromosome has three non-alpha chain genes. We describe here a Welsh family in which three members have five alpha-globn increased alpha mRNA output and it may therefore produce the phenotype of mild beta-thalassaemia.
mesh_terms: D004262:DNA Restriction Enzymes; D005796:Genes; D008040:Genetic Linkage; D005838:Genotype; D005914:Globins / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D012333:RNA, Messenger / Q000235:genetics; D013789:Thalassemia / Q000235:genetics*
chemical_list: D012333:RNA, Messenger; D005914:Globins; D004262:DNA Restriction Enzymes