Sarcomere protein gene mutations cause hypertrophic cardiomyopathy (HCM), a disease with distinctive histopathology and increased susceptibility to cardiac arrhythmias and risk for sudden death. Myocyte disarray (disorganized cell-cell contact) and cardiac fibrosis, the prototypic but protean features of HCM histopathology, are presumed triggers for ventricular arrhythmias that precipitate sudden death events. To assess relationships between arrhythmias and HCM pathology without confounding human variables, such as genetic heterogeneity of disease-causing mutations, background genotypes, and lifestyles, we studied cardiac electrophysiology, hypertrophy, and histopathology in mice engineered to carry an HCM mutation. Both genetically outbred and inbred HCM mice had variable susceptibility to arrhythmias, differences in ventricular hypertrophy, and variable amounts and distribution of histopathology. Among inbred HCM mice, neither the extent nor location of myocyte disarray or cardiac fibrosis correlated with ex vivo signal conduction properties or in vivo electrophysiologically stimulated arrhythmias. In contrast, the amount of ventricular hypertrophy was significantly associated with increased arrhythmia susceptibility. These data demonstrate that distinct somatic events contribute to variable HCM pathology and that cardiac hypertrophy, more than fibrosis or disarray, correlates with arrhythmic risk. We suggest that a shared pathway triggered by sarcomere gene mutations links cardiac hypertrophy and arrhythmias in HCM.fibrosis ͉ somatic modifiers ͉ disarray ͉ electrophysiology ͉ left ventrical wall thickness

Primary hyperparathyroidism may present with non-specific symptoms, and this may be one reason why patients with coeliac disease fail to improve despite compliance with a gluten-free diet. Seven case reports of primary hyperparathyroidism due to sporadic adenoma occurring in a series of 310 patients with coeliac disease are presented, highlighting the importance of looking for this condition in this population group. A prevalence of primary hyperparathyroidism of 2.3% in this series suggests a significant association between hyperparathyroidism and coeliac disease; most studies have indicated a prevalence of 3 in 1000 in the general population, although one study found that it may be as high as 21 in 1000 in women aged 55–75 years. The average age of patients in our series was 59 years and all but one were women. Further studies are needed to establish a possible association between primary hyperparathyroidism and coeliac disease.