title: Gamma thalassemia resulting from the deletion of a gamma-globin gene.
abstract: The first example of a deletion of one of the two gamma globin genes has been characterized through an analysis of the DNA of the heterozygous parent of a homozygous newborn, using restriction endonuclease mapping techniques. A deletion of approximately 5 kb was observed which was probably caused by an unequal crossing-over between the -G gamma- and -A gamma- genes resulting in the formation of a -G gamma A gamma- hybrid gene. Data on proportions of G gamma and A gamma chains in newborn babies assumed to be heterozygous for the hybrid and normal genes suggest that this hybrid gene may be producing its A gamma chain at levels normally seen only for the G gamma chain.
mesh_terms: D000328:Adult; D002872:Chromosome Deletion; D004262:DNA Restriction Enzymes; D005260:Female; D005796:Genes; D006580:Genetic Carrier Screening; D005914:Globins / Q000235:genetics*; D006720:Homozygote; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D009693:Nucleic Acid Hybridization; D013789:Thalassemia / Q000235:genetics*
chemical_list: D005914:Globins; D004262:DNA Restriction Enzymes