[Use of a specific DNA probe to confirm sickle cell anemia in a caucasian woman].

A specific DNA probe containing part of the structural B-globulin gene was used to confirm the diagnosis of sickle cell anemia in a caucasian woman. The patient's genomic DNA was digested with the restriction endonuclease Dde I, fractioned by agarose electrophoresis and Southern blotting. Molecular hybridization was performed with the DNA probe prepared by chemical labelling with photobiotin. The beta 8/beta 8 genotype rendered only 1 fragment of length 376 bp. Upon digestion with Dde I, the DNA of an individual with the normal genotype containing the enzyme recognition sequence at the site of sickle cell mutation, resulted in 2 fragments of 201 and 175 bp. The pedigree of the patient's caucasian family was studied by Hb electrophoresis. Four out of 7 brothers carried the sickle cell trait.