PMP22 related neuropathies: Charcot-Marie-Tooth disease type 1A and Hereditary Neuropathy with liability to Pressure Palsies

PMP22 related neuropathies comprise (1) PMP22 duplications leading to Charcot-Marie-Tooth disease type 1A (CMT1A), (2) PMP22 deletions, leading to Hereditary Neuropathy with liability to Pressure Palsies (HNPP), and (3) PMP22 point mutations, causing both phenotypes. Overall prevalence of CMT is usually reported as 1:2,500, epidemiological studies show that 20-64% of CMT patients carry the PMP22 duplication. The prevalence of HNPP is not well known. CMT1A usually presents in the first two decades with difficulty walking or running. Distal symmetrical muscle weakness and wasting and sensory loss is present, legs more frequently and more severely affected than arms. HNPP typically leads to episodic, painless, recurrent, focal motor and sensory peripheral neuropathy, preceded by minor compression on the affected nerve. Electrophysiological evaluation is needed to determine whether the polyneuropathy is demyelinating. Sonography of the nerves can be useful. Diagnosis is confirmed by finding respectively a PMP22 duplication, deletion or point mutation. Differential diagnosis includes other inherited neuropathies, and acquired polyneuropathies. The mode of inheritance is autosomal dominant and de novo mutations occur. Offspring of patients have a chance of 50% to inherit the mutation from their affected parent. Prenatal testing is possible; requests for prenatal testing are not common. Treatment is currently symptomatic and may include management by a rehabilitation physician, physiotherapist, occupational therapist and orthopaedic surgeon. Adult CMT1A patients show slow clinical progression of disease, which seems to reflect a process of normal ageing. Life expectancy is norma

RBM20 Mutations Induce an Arrhythmogenic Dilated Cardiomyopathy Related to Disturbed Calcium Handling

BACKGROUND: Mutations in RBM20 (RNA-binding motif protein 20) cause a clinically aggressive form of dilated cardiomyopathy, with an increased risk of malignant ventricular arrhythmias. RBM20 is a splicing factor that targets multiple pivotal cardiac genes, such as Titin (TTN) and CAMK2D (calcium/calmodulin-dependent kinase II delta). Aberrant TTN splicing is thought to be the main determinant of RBM20-induced dilated cardiomyopathy, but is not likely to explain the increased risk of arrhythmias. Here, we investigated the extent to which RBM20 mutation carriers have an increased risk of arrhythmias and explore the underlying molecular mechanism

Legius Syndrome in Fourteen Families

Legius syndrome presents as an autosomal dominant condition characterized by café-au-lait macules with or without freckling and sometimes a Noonan-like appearance and/or learning difficulties. It is caused by germline loss-of-function SPRED1 mutations and is a member of the RAS-MAPK pathway syndromes. Most mutations result in a truncated protein and only a few inactivating missense mutations have been reported. Since only a limited number of patients has been reported up until now, the full clinical and mutational spectrum is still unknown. We report mutation data and clinical details in fourteen new families with Legius syndrome. Six novel germline mutations are described. The Trp31Cys mutation is a new pathogenic SPRED1 missense mutation. Clinical details in the 14 families confirmed the absence of neurofibromas, and Lisch nodules, and the absence of a high prevalence of central nervous system tumors. We report white matter T2 hyperintensities on brain MRI scans in 2 patients and a potential association between postaxial polydactyly and Legius syndrome. © 2010 Wiley-Liss, Inc

Heritability in genetic heart disease : the role of genetic background

Background Mutations in genes encoding ion channels or sarcomeric proteins are an important cause of hereditary cardiac disease. However, the severity of the resultant disease varies considerably even among those with an identical mutation. Such clinical variation is often thought to be explained largely by differences in genetic background or ` modifier genes'. We aimed to test the prediction that identical genetic backgrounds result in largely similar clinical expression of a cardiac disease causing mutation, by studying the clinical expression of mutations causing cardiac disease in monozygotic twins. Methods We compared first available clinical information on 46 monozygotic twin pairs and 59 control pairs that had either a hereditary cardiomyopathy or channelopathy. Results Despite limited power of this study, we found significant heritability for corrected QT interval (QTc) in long QT syndrome (LQTS). We could not detect significant heritability for structural traits, but found a significant environmental effect on thickness of the interventricular septum in hypertrophic cardiomyopathy. Conclusions Our study confirms previously found robust heritability for electrical traits like QTc in LQTS, and adds information on low or lacking heritability for structural traits in heritable cardiomyopathies. This may steer the search for genetic modifiers in heritable cardiac disease.Peer reviewe

MYH7 p.(Arg1712Gln) is pathogenic founder variant causing hypertrophic cardiomyopathy with overall relatively delayed onset

Introduction: The MYH7 c.5135G &gt; A p.(Arg1712Gln) variant has been identified in several patients worldwide and is classified as pathogenic in the ClinVar database. We aimed to delineate its associated phenotype and evaluate a potential founder effect.Methods: We retrospectively collected clinical and genetic data of 22 probands and 74 family members from an international cohort.Results: In total, 53 individuals carried the MYH7 p.(Arg1712Gln) variant, of whom 38 (72%) were diagnosed with hypertrophic cardiomyopathy (HCM). Mean age at HCM diagnosis was 48.8 years (standard deviation: 18.1; range: 8–74). The clinical presentation ranged from asymptomatic HCM to arrhythmias (atrial fibrillation and malignant ventricular arrhythmias). Aborted sudden cardiac death (SCD) leading to the diagnosis of HCM occurred in one proband at the age of 68 years, and a family history of SCD was reported by 39% (5/13) probands. Neither heart failure deaths nor heart transplants were reported. Women had a generally later-onset disease, with 14% of female carriers diagnosed with HCM at age 50 years compared with 54% of male carriers. In both sexes, the disease was fully penetrant by age 75 years. Haplotypes were reconstructed for 35 patients and showed a founder effect in a subset of patients.Conclusion: MYH7 p.(Arg1712Gln) is a pathogenic founder variant with a consistent HCM phenotype that may present with delayed penetrance. This suggested that clinical follow-up should be pursued after the seventh decade in healthy carriers and that longer intervals between screening may be justified in healthy women &lt; 30 years.</p

A Dutch MYH7 founder mutation, p.(Asn1918Lys), is associated with early onset cardiomyopathy and congenital heart defects

Background Mutations in the myosin heavy chain 7 (MYH7) gene commonly cause cardiomyopathy but are less frequently associated with congenital heart defects. Methods In th

Effectiveness of life skills training on increasing self-esteem of high school students

AbstractObjective This study designed to investigate effectiveness of training life skills on adolescents’ students. Method This study is a pseudo-experimental study which accomplished on 160 students in Karaj city. Subjects of the study selected randomly from list of students in all of the schools of Karaj; then they divided randomly in two groups. Trained counsellors taught the life skills to students of the study group, and 80 reminder subjects assigned as control group. After educating the training program, subjects administered Cooper Smith self-esteem questionnaire (58-items version). Results Findings of the study indicated that life skills training lead to significant increase of self-esteem in study group in contrast to control group subjects. Conclusion Psycho education and mental health programs such as life skills training could cause to increase the necessary skills in students and decline school and educational problems

Hereditary leiomyomatosis and renal cell cancer presenting as metastatic kidney cancer at 18 years of age: implications for surveillance

Hereditary leiomyomatosis and renal cell cancer (HLRCC) is an autosomal dominant syndrome characterized by skin piloleiomyomas, uterine leiomyomas and papillary type 2 renal cancer caused by germline mutations in the fumarate hydratase (FH) gene. Previously, we proposed renal imaging for FH mutation carriers starting at the age of 20 years. However, recently an 18-year-old woman from a Dutch family with HLRCC presented with metastatic renal cancer. We describe the patient and family data, evaluate current evidence on renal cancer risk and surveillance in HLRCC and consider the advantages and disadvantages of starting surveillance for renal cancer in childhood. We also discuss the targeted therapies administered to our patient

DNA analysis in inherited cardiomyopathies: Current status and clinical relevance

Most hypertrophic cardiomyopathies and a subset of dilated and arrhythmogenic right ventricular cardiomyopathies are familial diseases. They generally show an autosomal dominant pattern of inheritance and have underlying mutations in genes encoding sarcomeric, cytoskeletal, nuclear envelope, and desmosomal proteins. DNA analysis in cardiomyopathies can help diagnose borderline cases, and cascade screening of family members can identify individuals at risk. Genotype-phenotype relations are comlex, but some associations, such as septal morphology, electrocardiogram parameters, and additional cardiac and other manifestations, point toward certain genes. Such features help target DNA testing and the results of DNA analysis con be used in making clinical decisions