Familial occurrence of LGL leukaemia.

The aetiology of LGL leukaemia is now known; however, we recently detected HTLV-II from such a patient. We describe here the occurrence of LGL leukaemia in a mother and her son. Serum from the son reacted to HTLV-I/II gag proteins, but not a recombinant HTLV-I env protein p21e; serum from the mother was negative. PCR analyses in both patients were negative for pX and pol sequences shared by HTLV-I/II and also for specific gag sequences of HTLV-I and HTLV-II. These data show that familial cases of LGL leukaemia are not associated with prototypical HTLV-I or HTLV-II infection.