Familial Burkitt's lymphoma in Nigerians.

Three Nigerian sib-pairs with familial Burkitt's lymphoma (BL) seen between 1986 and 1996 are described. Their ages ranged from 4 to 20 years (median 9.5), and there were five males and one female. The mean age interval between each pair at presentation was 4 years (3-6) and the mean time interval 22 months (0.3-41). Two of the sib-pairs were sex-concordant, including a set of monozygotic twins. Five of the patients presented in stage C and one in stage A. Parental consanguinity was not found in any group. Space-clustering was confirmed in all three but time-clustering in only one. The occurrence of BL in multiple members of the same family, the presence of sex concordance and the relatively wide variation in the time of onset of disease between each pair suggest genetic predisposition as a possible additional aetiological factor for BL in the families affected.