HEREDITARY OSTEO-ONYCHO-RENAL DYSPLASIA WITH EXCESS URINARY PYRIDINOLINE CROSS-LINKS AND ABNORMAL KIDNEY COLLAGEN CROSS-LINKING

HOOD syndrome is a rare genetic disorder also known as nail patella sy ndrome. Biochemical and molecular biological data are rare and not con clusive. Preliminary data suggest the involvement of collagen type IV. This would, however, not be enough to explain nail or bone involvemen t. As kidney pathology would be consistent with a cross-linking disord er, we tested collagen IV and kidney collagen cross-linking on SDS-PAG E. This method showed a remarkable reduction in high-molecular-weight collagen polymers. The patient's and his mother's urinary pyridinoline cross-link excretion was manifold increased. Disturbed cross-linking of connective tissue proteins would help to explain the multiorgan inv olvement.