A novel locus for syndromic chronic idiopathic intestinal pseudo-obstruction maps to chromosome 8q23-q24

Chronic idiopathic intestinal pseudo-obstruction (CIIP) is a rare and severe clinical syndrome characterized by symptoms and signs of intestinal occlusion, in the absence of any mechanical obstruction of the gut lumen. In the attempt to identify the genetic basis of CIIP, we analyzed a Turkish pedigree with a high degree of consanguinity in which three siblings presented with a syndromic form of CIIP. All affected family members were characterized by recurrent, self-limiting subocclusive episodes, long-segment Barrett esophagus, and a variety of minor cardiac valve or septal defects. In some patients full-thickness intestinal biopsy samples were obtained and tissues were processed for immunohistochemistry using antibodies to different markers of the intestinal neuromuscular tract. Full-thickness biopsies of the gut wall showed abnormalities of both the neural and muscular components suggesting an underlying intestinal neuro-myopathy. Blood samples were collected for DNA extraction from each available family member and DNAs were genotyped using 382 microsatellites spanning the entire genome with the aim to take advantage of the homozygosity mapping approach. Linkage analysis identified a new syndromic locus on chromosome 8q23-q24 (multipoint LOD score=5.01). Our data strongly support the presence of a new genetic locus associated with CIIP, long-segment Barrett esophagus, and cardiac involvement on chromosome 8.