A new syndrome of Crohn's disease and pachydermoperiostosis in a family.

Few syndromic associations with Crohn's disease are described. The aim of this study was to characterize a new syndrome of Crohn's disease associated with pachydermoperiostosis in 3 brothers. Three probands, 6 siblings, both parents, 20 of 21 third-generation relatives, and 9 spousal controls were evaluated. Serological evaluation for antineutrophil cytoplasmic antibodies and human leukocyte antigens as well as genetic testing for tumor necrosis factor microsatellites, intercellular adhesion molecule 1 polymorphisms, the interleukin 1 receptor antagonist gene, and the interleukin 1 beta gene were performed. Only the 3 probands were affected and developed pachydermoperiostosis between ages 14 and 17 years. Pachydermoperiostosis preceded Crohn's ileocolitis by 6 and 20 years in two probands, excluding secondary hypertrophic osteoarthropathy. Two probands were antineutrophil cytoplasmic antibody positive vs. 1 of 27 unaffected relatives (P < 0.001, chi 2). Haplotypes for human leukocyte antigen and tumor necrosis factor microsatellites were discordant. The probands' generation was homozygous for the common allele 1 of the interleukin 1 receptor antagonist and interleukin 1 beta genes. Two probands carried a rare polymorphism of the intercellular adhesion molecule 1 gene. A new syndrome of Crohn's disease and pachydermoperiostosis associated with antineutrophil cytoplasmic antibodies is described. Inheritance is most likely autosomal recessive by pedigree. No clear association was found between this syndrome and the gene regions evaluated.