An Italian deficient G6PD variant associated with chronic non-spherocytic haemolytic anaemia (CNSHA) was biochemically characterised and studied at molecular level. Single-strand conformation polymorphism (SSCP) analysis led to the identification of an abnormal migration pattern of an amplified fragment encompassing exons 10 and 11 of the G6PD gene. Sequence analysis of both strands using an automated fluorescent DNA sequencer revealed a G-->A transition at nt. position 1246 in exon 10. A C-->T substitution at nt. 1311 in exon 11 was also found, which has already been described as a silent mutation common in Caucasians. The 1246 G-->A mutation has been described only in a Japanese subject with CNSHA (G6PD Tokyo) not associated with the 1311T polymorphism, suggesting that this mutation may have arisen independently in Europe and Asia.