HMG1 is not rearranged by 13q12 aberrations in lipomas

Several cytogenetic subgroups with characteristic lesions involving chromosomal regions 12q14-15, 6p21.3, or 13q12 can be distinguished in lipomas. Rearrangements of the HMGIC gene have been described in cases with 12q14-15 abnormalities, whereas HMGIY has been shown to be the target gene of 6p21.3 aberrations. Recently, HMG1, another member of the HMG family, was mapped to 13q12. The aim of this study was to investigate the possible role of HMG1 aberrations in lipomas with 13q12 abnormalities. Two PAC clones containing HMG1 were isolated. By molecular cytogenetic investigations using these PAC clones and by Southern blot analysis of eight lipomas with 13q12 abnormalities, we were able to show that these chromosomal rearrangements did not result in intragenic rearrangements of HMG1 or breakpoints close to it.