New Diagnostic Strategy in Hypertrophic Cardiomyopathy
New Diagnostic Strategy in Hypertrophic Cardiomyopathy
Hypertrophic cardiomyopathy (HCM) is an autosomal dominant disease characterized by
 unexplained hypertrophy of the left ventricle, often with predominant involvement of the
 interventricular septum, and characterized by myocyte disarray and fibrosis.

 HCM is the most common familial heart disease with strong genetic heterogeneity, demonstrated
 over the past 20 years. Mutations in 11 or more genes encoding proteins of the cardiac
 sarcomere are responsible for (or associated with) HCM.

 However, 30-40% of sporadic and familial cases of HCM are still genetically unlabelled. In
 addition, secondary HCM caused by Fabry's disease or amyloidosis, may mimic primary HCM and
 may be under diagnosed. This may result in a delay in accurate diagnosis and instauration of
 specific treatment, with possible clinical consequences for the patients.

 For these reasons, we decided to apply a new diagnostic strategy for patients with newly
 diagnosed HCM, including the whole exome sequencing (WES) technology.

 If correctly applied, this new technology has the potential to strongly reduce the diagnostic
 wavering leading to earlier diagnosis and genetic counseling in sarcomeric HCM and rarer
 forms of secondary HCM including Fabry's disease and amyloidosis, and also specific therapy
 set-up in secondary forms of HCM. It should also allow identifying new genes responsible for
 HCM.
Background : Hypertrophic cardiomyopathy (HCM) is an autosomal dominant disease characterized
 by unexplained hypertrophy of the left ventricle, often with predominant involvement of the
 interventricular septum, and characterized by myocyte disarray and fibrosis.

 HCM is the most common familial heart disease with strong genetic heterogeneity, demonstrated
 over the past 20 years. Mutations in 11 or more genes encoding proteins of the cardiac
 sarcomere are responsible for (or associated with) HCM.

 However, 30-40% of sporadic and familial cases of HCM are still genetically unlabelled. In
 addition, secondary HCM caused by Fabry's disease or amyloidosis, may mimic primary HCM and
 may be under diagnosed. This may result in a delay in accurate diagnosis and instauration of
 specific treatment, with possible clinical consequences for the patients.

 Objectives : For these reasons, we decided to apply a new diagnostic strategy for patients
 with newly diagnosed HCM, including the whole exome sequencing (WES) technology.

 1. Main objective: to evaluate the additional diagnostic value of the new proposed strategy
 for the identification of a specific cause of HCM as compared with conventional
 diagnostic strategy

 2. Secondary objectives:

 To evaluate the frequency of secondary HCM (Fabry's disease, amyloidosis, mitochondrial
 cardiomyopathies, and others) observed by this systematic screening in a population of newly
 diagnosed HCM

 Perspectives: If correctly applied, this new technology has the potential to strongly reduce
 the diagnostic wavering leading to earlier diagnosis and genetic counseling in sarcomeric HCM
 and rarer forms of secondary HCM including Fabry's disease and amyloidosis, and also specific
 therapy set-up in secondary forms of HCM. It should also allow identifying new genes
 responsible for HCM.
Inclusion Criteria:

 -  patient with newly diagnosed hypertrophic cardiomyopathy (HCM), based on conventional
 echocardiographic criteria.The diagnosis of HCM will be considered definite in the
 presence of left ventricle hypertrophy without cavity dilatation and without other
 cardiac or systemic disease able to produce the magnitude of hypertrophy.

 Exclusion Criteria:

 -  Associated cardiac or non cardiac disease known to cause left ventricle hypertrophy
 (uncontrolled systemic Hypertension, severe aortic stenosis)