G6PD Ciudad de la Habana: a new slow variant with deficiency found in a Cuban family.

A new G6PD variant has been detected in a Cuban male and there is no evidence of associated hematological abnormalities. The main characteristics of this variant, moderate deficiency, slow electrophoretic mobility, increased utilization of the substrate analogues, and a different chromatographic behavior, indicate that it is a variant that has not been previously described.