[Somatic mutations of PIG-A gene in Chinese patients with paroxysmal nocturnal hemoglobinuria].

OBJECTIVE: To explore the somatic mutations of PIG-A gene in Chinese patients with paroxysmal nocturnal hemoglobinuria (PNH) and to compare these mutations with those in non-Chinese PNH patients.

METHODS: Seven overlapping regions of PIG-A cDNA from granulocytes of 4 PNH patients were amplified by RT-PCR. The mutant segments were identified by HA/SSCP and then cloned and sequenced.

RESULTS: In 4 Chinese PNH patients five small PIG-A mutations were found, including four single base substitutions (resulting in 1 consense mutations and 3 missense mutations) and one single base deletion causing a frameshift). These mutations were all different and distributed in different locations of the gene.

CONCLUSION: The PIG-A mutations in our patients occurred at random sites and no mutation hot spot was found. Compared with Japanese, British, American and Tai patients, Chinese patients seem to have more single base substitutions and less frameshift. The pattern of mutations in our patients is similar to that in Japanese patients but different from that in other races. These suggest that mutagens might be different in the pathogenesis of PNH in different regions.