NEUROFIBROMATOSIS AND CHILDHOOD LEUKAEMIA LYMPHOMA - A POPULATION-BASED UKCCSG STUDY/

There is a well-known raised risk of leukaemia in children with neurof ibromatosis type 1 (NF-1). We carried out the first detailed populatio n-based study of leukaemia and non-Hodgkin lymphoma (NHL) associated w ith NF-1 in order to estimate the risk and elucidate the relationship between these conditions. Over the 17 year study period there were fiv e cases of chronic myelomonocytic leukaemia (CMML) in patients with NF -1 (relative risk 221; 95% CI 71-514), 12 cases of acute lymphoblastic leukaemia (ALL) (relative risk 5.4; 95% CI 2.8-9.4) and five cases of NHL (relative risk 10.0; 95% CI 3.3-23.4). Marrow cytogenetics could be reviewed for seven patients. Specific abnormalities found were mono somy 21 in a child with CMML and 7p+, 17p- in a child with ALL. No abn ormalities were reported of 17q, which includes the NF1 gene. CMML occ urred predominantly in boys, who also had a family history of NF-1. AL L and NHL were more often found in children with no previous family hi story.