Background-Myxomatous dystrophy of the cardiac valves affects Ϸ3% of the population and remains one of the most common indications for valvular surgery. Familial inheritance has been demonstrated with autosomal and X-linked transmission, but no specific molecular abnormalities have been documented in isolated nonsyndromic forms. We have investigated the genetic causes of X-linked myxomatous valvular dystrophy (XMVD) previously mapped to chromosome Xq28. Methods and Results-A familial and genealogical survey led us to expand the size of a large, previously identified family affected by XMVD and to refine the XMVD locus to a 2.5-Mb region. A standard positional cloning approach identified a P637Q mutation in the filamin A (FLNA) gene in all affected members. Two other missense mutations (G288R and V711D) and a 1944-bp genomic deletion coding for exons 16 to 19 in the FLNA gene were identified in 3 additional, smaller, unrelated families affected by valvular dystrophy, which demonstrates the responsibility of FLNA as a cause of XMVD. Among carriers of FLNA mutation, the penetrance of the disease was complete in men and incomplete in women. Female carriers could be mildly affected, and the severity of the disease was highly variable among mutation carriers. Conclusions-Our data demonstrate that FLNA is the first gene known to cause isolated nonsyndromic MVD. This is the first step to understanding the pathophysiological mechanisms of the disease and to defining pathways that may lead to valvular dystrophy. Screening for FLNA mutations could be important for families affected by XMVD to provide adequate follow-up and genetic counseling.

Gut 2003;52:84-90 Background: Morphological and functional changes in the enteric nervous system (ENS) have been reported in inflammatory bowel diseases but it is still uncertain whether neurochemical coding of myenteric neurones is altered in ulcerative colitis (UC). Aims: In this study we investigated transmitter co-localisation in myenteric neurones of normal colon and the colon of patients with UC. Methods: Choline acetyltransferase (ChAT), neurone specific enolase (NSE), vasoactive intestinal peptide (VIP), and substance P (SP) were detected by immunohistochemical methods in whole mounts of colonic myenteric plexus of UC patients (n=10) and controls (n=8). Results: The proportion of ChAT positive and VIP positive neurones relative to the NSE population did not differ in inflamed (33.3% and 9.3%, respectively) and non-inflamed segments (33.6% and 9.7%) of UC colon compared with controls (35.0% and 6.9%). The proportion of SP positive neurones was significantly larger in both inflamed (15.5%) and non-inflamed (20.3%) segments than in controls (5.9%). Analysis of changes in subpopulations showed that 26.9% of neurones were only ChAT positive in controls but that the proportion was significantly smaller in inflamed (18.8%) and non-inflamed (15.8%) areas of UC. The proportions of neurones containing ChAT and SP were significantly higher in inflamed (11.8%) and non-inflamed (13.9%) areas than in controls (5.0%). Conclusion: Remodelling of myenteric neurones in UC involves a shift from mainly cholinergic to more SP positive innervation. This effect may constitute part of the neuronal basis for the motility disturbances observed in UC.

Tissue-based measurements of specific pathogenesis-based transcripts reflecting NK burden, endothelial activation, macrophage burden, and interferon-γ effects accurately classify AMR and correlate with degree of injury and disease activity. This study illustrates the clinical potential of a tissue-based analysis of gene transcripts to refine diagnosis of heart transplant rejection.