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Introduction: Leigh Syndrome is an uncommon cause of infantile apnea., Case Summary: We report a 5-month-old girl with sudden respiratory arrest followed by episodic hyper- and hypo-ventilation, encephalopathy, and persistent lactic acidosis. Computed tomography of the brain revealed symmetric low densities over the basal ganglia, internal capsule, thalami, and midbrain. Cardiac echocardiogram was suggestive of hypertrophic cardiomyopathy., Discussion: Diagnosis of Leigh syndrome due to T8993G mutation was confirmed with polymerase chain reaction and direct DNA sequencing of mitochondrial genome. To our knowledge, this is the first report of proven maternally inherited Leigh syndrome in Hong Kong.

Hypertrophic cardiomyopathy (HCM) is a common cardiac disease that is now being identified in the pediatric population. The etiology of this disease is largely genetic, and as a result, genetics professionals are becoming more involved in the management of these patients. We present multiple case scenarios that highlight the complex nature of this disease and how genetic counselors and cardiologists can interact to identify the genetic etiology of HCM and provide comprehensive care for these patients. Additionally, we describe knowledge gaps in this field and how research endeavors can assist in more effectively managing this patient cohort.

Building on seminal studies of the last 20 years, genetic testing for hypertrophic cardiomyopathy (HCM) has become a clinical reality in the form of targeted exonic sequencing of known disease-causing genes. This has been driven primarily by the decreasing cost of sequencing, but the high profile of genome-wide association studies, the launch of direct-to-consumer genetic testing, and new legislative protection have also played important roles. In the clinical management of hypertrophic cardiomyopathy, genetic testing is primarily used for family screening. An increasing role is recognized, however, in diagnostic settings: in the differential diagnosis of HCM; in the differentiation of HCM from hypertensive or athlete's heart; and more rarely in preimplantation genetic diagnosis. Aside from diagnostic clarification and family screening, use of the genetic test for guiding therapy remains controversial, with data currently too limited to derive a reliable mutation risk prediction from within the phenotypic noise of different modifying genomes. Meanwhile, the power of genetic testing derives from the confidence with which a mutation can be called present or absent in a given individual. This confidence contrasts with our more limited ability to judge the significance of mutations for which co-segregation has not been demonstrated. These variants of "unknown" significance represent the greatest challenge to the wider adoption of genetic testing in HCM. Looking forward, next-generation sequencing technologies promise to revolutionize the current approach as whole genome sequencing will soon be available for the cost of today's targeted panel. In summary, our future will be characterized not by lack of genetic information but by our ability to effectively parse it.

Hypertrophic cardiomyopathy (HCM) is considered to be a genetic disease. As such, multidisciplinary approach is needed to evaluate and treat this condition. We present several patient vignettes to illustrate the complementary skills of cardiologists and genetic counselors in providing comprehensive care. Translational application of research will continue to expand as more genetic causes of HCM will be recognized and more genetic tests will become available. Now is the opportunity to build a strong collaboration between the two disciplines to be prepared for the era of personalized medicine.

Hypertrophic cardiomyopathy (HCM) is an epidemiologically relevant, worldwide spread condition which is frequently perceived as a rare disease. This misconception might be supported by some characteristics of HCM such as its incomplete penetrance and variable age at onset and by the fact that many patients remain asymptomatic for a long course of the disease and are thus unlikely to seek for medical evaluation. Multiple evidences suggest that early diagnosis of HCM is important, not only because it allows the patients to be addressed to appropriate diagnostic work-out and to adequate therapeutical options but because it may trigger the screening of family members with the potential of further, new diagnosis of HCM in previously unsuspected individuals. Increased awareness of the disease among physicians working in community-based hospitals and in outpatients facilities, and a facilitated communication and access to tertiary referral centers, will result into a wider knowledge of the spectrum of the disease, a better access to the state-of-the-art management options for patients, and to a more diffuse practice of genetic evaluation of HCM families.

Hereditary forms of hypertrophic, dilated, restrictive, and right ventricular cardiomyopathies are frequently seen. Patterns of inheritance include autosomal dominant, autosomal recessive, X-linked, and matrilinear. Recognition of the mode of inheritance facilitates proper clinical screening of family members in subsequent generations. Report of successful sequence analysis of the human genome 7 years ago has resulted in widespread translation of genomic information into clinical applications. As technologic advances in high throughput sequence determination continue to evolve, an era of personalized medicine based on genomic data is highly anticipated. Today, clinical genetic testing is available for most monogenic forms of cardiomyopathy and the demand among patients and families is increasing. However, physicians and patients should consider the benefits and limitations of such testing. This review will focus on inherited forms of cardiomyopathy, detailing the currently available genetic tests, as well as benefits, limitations, and possible outcomes of such testing.

A 27 year old female with Noonan syndrome and hypertrophic cardiomyopathy underwent cardiovascular magnetic resonance imaging. These images showed asymmetrical septal hypertrophy with maximal left ventricular end-diastolic wall thickness of 25 mm. Following administration of gadolinium, areas of hyperenhancement were seen in the anterior, anteroseptal and lateral walls. This is the first report of focal gadolinium hyperenhancement in hypertrophic cardiomyopathy due to Noonan syndrome and suggests that myocardial fibrosis can be imaged by MR hyperenhancement as seen previously in sarcomeric hypertrophic cardiomyopathy.