High-resolution band analysis was performed in order to precisely determine the breakpoints of a de novo chromosome translocation, t(1;7), which is associated with clinical signs of HMC syndrome (McKusick's #239800). The breakpoints were found to be at 1q31.2 and 7p15.1-p15.3, respectively. The finding of the translocation in this case might not be coincidental, but rather suggestive of the gene locus responsible for the development of HMC syndrome at either site of the breakpoints.