Genetic Counseling in Inherited Cardiomyopathies

ignificant advances in genetic testing have provided new opportunities for cardiologists to identify and understand the genetic basis of inherited cardiomyopathies (CMPs).Over the past 10 years, genetic testing has transitioned from research to the clinical arena and is routinely offered in CMP clinics to identify the genetic cause of disease (1).However, this testing also has come with new challenges and responsibilities regarding the use of this information for patients with CMPs and their families.GENETIC COUNSELING Genetic counseling is "the process of helping people understand and adapt to the medical, psychological, and familial implications of genetic contributions to disease" (2).All medical professionals, including cardiologists, who treat families with CMPs should have a good knowledge of molecular genetics of CMP and be trained in the principles of genetic counseling (1,3,4).The provision of care for CMP requires a multidisplinary team in which genetics providers play an essential role.Genetic counseling is an integral part of the management for all patients with CMPs and their family members, and specialized CMP centers increasingly have genetic counselors and/or clinical geneticists as a part of the team.ROLE AND COMPONENTS OF GENETIC COUNSELING PSYCHOLOGICAL ASPECTS.Communication of information can be carried out by any member of the team with necessary competencies.(Figure 1).However, genetic counselors are trained in the genetic basis and psychological impact of disease.At the time of genetic counseling, affected individuals and their families may be struggling with anxiety related to their recent diagnosis, uncertainty about therapy and their longevity, inheritance in other family members, or grief related to the sudden death of a loved one.Many psychosocial issues should be addressed during counseling.Many feelings may be expressed, such as apprehension about idea of being "labeled" with this condition, guilt about passing on the gene to their children, and feelings related to the impact of the diagnosis on lifestyle, employment, and insurance.MODE AND RISK OF INHERITANCE.Clinical assessment and family history with construction of a 3-to 4-generation family pedigree helps to confirm the genetic origin and mode of inheritance.In some instances, this may require collection of relatives' medical records or post-mortem reports.Establishing the mode of inheritance identifies relatives who are at risk of disease development.Most CMPs are typicallyinherited as an autosomal dominant trait as a result of a single gene defect capable of causing the trait (i.e., monogenic origin).Thus, there is a 50% risk for firstdegree relatives to be affected by the same condition.Other modes of inheritance, such as autosomal recessive, X-linked recessive, or matrilinear inheritance, may be suspected or identified during assessment of the family history and pedigree.In some X-linked disorders such as Fabry disease, identification of the modes of inheritance may be challenging because female carriers may develop a milder phenotype later in life.In autosomal recessive CMP,