The breakpoints of a constitutional inversion of chromosome 9 associated with haemophagocytic lymphohistiocytosis are not linked to the disease gene

Haemophagocytic lymphohistiocytosis (HLH) is a severe disorder of early inf ancy consistent with an autosomal recessive inheritance. Neither the geneti c locus nor the biochemical defect is known for the disease. A constitution al pericentric inversion of chromosome 9, with breakpoints in bands 9p23 an d 9q31, has been reported in a case of HLH, suggesting a possible relations hip between this chromosome abnormality and the disease. We investigated su ch an association, performing a genetic linkage analysis in a set of ave co nsanguineous HLH families. 27 polymorphic markers on chromosome 9 were stud ied, excluding most of chromosome 9 as a putative site for the HLH gene.