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Biomedical subjects

A Perrot

Publications and source records attributed to A Perrot.

At least 19 recordsLinked to original sources
PubMed2005

[Sudden cardiac death in familial hypertrophic cardiomyopathy. Identification of high-risk patients].

Hypertrophic cardiomyopathy (HCM) is a relatively frequent, genetically determined primary cardiomyopathy, characterized by most often asymmetric hypertrophy of the ventricular septum with or without systolic obstruction of the left ventricular outflow tract. HCM is a genetically heterogeneous disease, with 12 different disease-causing genes beeing indentified to date. Histologically the disease is characterized by hypertophy and disarray of myofibrils as well as by an increase in myocardial fibrosis. Clinically, these changes may lead to palpitations, dyspnoe on exertion, and/or angina pectoris. However, they also lead to an increased propensity to the development of severe ventricular tachyarrhythmias and sudden cardiac death. The incidence of sudden death is significantly increased in HCM, particularly in affected young subjects. Risk stratification in HCM should include a complete clinical-cardiological evaluation that should also consider new diagnostic features, e. g. MR imaging. Major risk factors for sudden cardiac death include a survived cardiac arrest (ventricular fibrillation), non-sustained and sustained ventricular tachycardia, a history of premature familial sudden death, unexplained syncope, an abnormal blood pressure response on exercise, and left ventricular thickness greater than or equal to 3 cm. Ideally, risk stratification should also include genetic testing, since some gene mutations seem to be associated with a higher risk for sudden cardiac death than others. However, genetic testing in HCM in not yet available on a routine basis. The implantation of a cardioverter/defibrillator is first-line therapy in patients with documented ventricular tachycardia/fibrillation or patients who have survived sudden cardiac death. These devices also play an important role in the primary prevention of sudden cardiac death in HCM. Algorithms and scores are available to estimate the risk of sudden death, however, the decision to implant a cardioverter/defibrillator remains an individual decision in every single patient.

Blood Pressure↗
PubMed2005

[Cardiac manifestations of muscular dystrophies].

Muscular dystrophies (MD) are a clinically and genetically heterogeneous disease group. In the last few years, remarkable progress has been made in understanding the close und various relations between skeletal muscle disease and heart muscle disease. Cardiac involvement has been documented in a number of primary MDs and is even the dominant feature in some of them. The myocardium can be affected in the form of a dilated cardiomyopathy while the conduction system can be affected resulting in arrhythmias and conduction defects. Many patients with MD die because of cardiac complications like sudden cardiac death or congestive heart failure. Detailed clinical data about cardiac involvement are available for Duchenne/Becker MD, Emery-Dreifuss MD, myotonic dystrophy, and the different limb girdle MDs. Cardiac manifestations were also found in congenital MD, central core disease, proximal myotonic myopathy, and nemaline myopathy. No data about cardiac abnormalities are available in oculopharyngeal MD and rippling muscle disease. The heart of patients with primary MD should be carefully investigated because of the life-threatening events caused by cardiac complications. There is a strong need for a close collaboration between neurologists and cardiologists in order to provide optimal disease management for the affected patients.

Arrhythmias, Cardiac↗
PubMed2002

The heart in Anderson Fabry disease.

Anderson Fabry disease is a life threatening, X-linked inborn metabolic defect of the lysosomal enzyme áalpha-galactosidase A. The deficiency of alpha-galactosidase A leads to a progressive accumulation of globotriaosylceramide (Gb(3)), the major glycosphingolipid substrate of the enzyme, within vulnerable cells, tissues, and organs, including the cardiovascular system. Cardiac involvement is frequent and patients with cardiac affection develop progressive hypertrophic infiltrative cardiomyopathy, valvular abnormalities, arrhythmias, and conduction abnormalities and may develop coronary heart disease. Hemizygous male patients have no detectable alpha-galactosidase A activity, while affected heterozygous females may have normal level of alpha-galactosidase A activity. Death occurs in male patients at 45 to 50 years, about 15 to 20 years earlier than in female patients due to a vicious circle from chronic renal insufficiency, arterial hypertension, atherosclerotic lesions and cerebrovascular hemorrhage or insults, and cardiomyopathy. Cardiac involvement in hetero- and hemizygotes will be discussed as well as the influence of enzyme replacement of alpha-galactosidase A.

Adult↗
PubMed2001

The GAA repeat expansion in intron 1 of the frataxin gene is related to the severity of cardiac manifestation in patients with Friedreich's ataxia.

Friedreich's ataxia is an autosomal recessive disorder characterized by spinocerebellar degeneration. It is caused by an unstable GAA trinucleotide repeat expansion (>120 repeats) in the first intron of the frataxin gene on chromosome 9 (9q13) in both alleles. Concentric left ventricular hypertrophy has been recognized as the major cardiac manifestation of Friedreich's ataxia. Our aim was to investigate the influence of the frataxin repeat length on cardiac hypertrophy in patients with Friedreich's ataxia and in patients with hypertrophic and dilated cardiomyopathy. Thirty-one patients with Friedreich's ataxia, 86 patients with hypertrophic cardiomyopathy, 134 patients with dilated cardiomyopathy, and 32 healthy individuals without cardiac disease were analysed by electrocardiography and 2D-M-mode echocardiography. Then, the size of the frataxin repeat was determined by polymerase chain reaction (PCR) and agarose gel electrophoresis. The number of GAA repeats in patients with hypertrophic and dilated cardiomyopathy was not different from the length in patients without cardiac disease (hypertrophic cardiomyopathy, 8+/-2 repeats on GAA 1 allele and 11+/-5 repeats on GAA 2 allele; dilated cardiomyopathy, 7+/-2 repeats on GAA 1 allele and 11+/-5 repeats on GAA 2 allele; Control, 9+/-1 repeats on GAA 1 allele and 12+/-6 repeats on GAA 2 allele). The septal and posterior wall thickness of these patients was not related to the GAA repeat length. All patients with Friedreich's ataxia had two enlarged alleles with a mean GAA repeat length of 757+/-316 and 1012+/-231, respectively. The lengths of both alleles were significantly greater than the lengths in the controls (P<0.0001), patients with hypertrophic cardiomyopathy (P<0.0001) and dilated cardiomyopathy (P<0.0001). A significant correlation was revealed between interventricular septal hypertrophy and frataxin repeat length in the smaller allele. Furthermore, the ratio of septal to posterior wall thickness was significantly correlated to GAA repeat size on the smaller allele. In conclusion, the size of the GAA repeat on the smaller allele in the frataxin gene is associated with the degree of left ventricular hypertrophy in patients with Friedreich's ataxia but is not related to the severity of hypertrophic cardiomyopathy.

Adult↗
PubMed2001

[Genetics of dilated cardiomyopathy].

Dilated cardiomyopathy is one of the leading causes of heart failure and a primary cause for heart transplantation in patients below the age of 40 years. Despite major advances in diagnostic procedures such as examination of myocardial biopsies, the etiology remains unknown in many patients. Chronic inflammation or myocarditis and chronic alcohol abuse are considered two main etiologic factors in dilated cardiomyopathy. A third causal factor, namely genetic transmission of the disease, is at least as common as myocardial inflammation or toxic damage. Several prospective studies of relatives of patients with dilated cardiomyopathy proved that about 25-30% of all cases are of familial etiology. The most common mode of inheritance is autosomal dominant. Less frequently is the disease inherited as an X-chromosomal trait. Autosomal recessive and mitochondrial transmission is rare. The penetrance is highly variable and age dependent. Many relatives of patients with DCM show only minor cardiac abnormalities and it is unknown whether they progress to full cardiomyopathy in later life. Examination of families has identified so far eight disease genes, namely the dystrophin, tafazzin, cardiac actin, desmin, lamin A/C, delta- sarcoglycan, cardiac beta-myosin heavy chain, and cardiac troponin T gene. Certain mutations in lamin A/C cause conduction system disease and dilated cardiomyopathy, whereas other mutations cause in addition skeletal muscle myopathy. Dystrophin mutations are the cause of the rare X-linked dilated cardiomyopathy without skeletal muscle involvement and a progressive course in young men. Other mutations in the dystrophin gene, mainly deletions, are the cause of the muscular dystrophy Becker and Duchenne which also present with dilated cardiomyopathy. Mutations of the desmin, delta-sarcoglycan, the cardiac actin and beta-myosin heavy chain as well as the troponin T gene are known to cause autosomal dominant-dilated cardiomyopathy without other abnormalities. The infantile X-linked DCM is caused by mutations of the tafazzin gene. The onset of the disease is typically within the first year of life and death occurs usually in childhood. Most patients may in addition be characterized by skeletal myopathy, short stature, neutropenia and abnormal mitochondria, also referred to as Barth syndrome. Knowledge of the DCM disease genes led to the new hypothesis that dilated cardiomyopathy is a disease of the myocardial force generation or force transmission. Many more disease loci are known but the responsible disease genes are not yet identified. Better understanding of the expression and function of disease genes may eventually result in new diagnostic and therapeutic tools in order to improve the prognosis of this severe disorder.

Actins↗
PubMed2001

SCAP ligands are potent new lipid-lowering drugs.

Upregulation of low-density lipoprotein receptor (LDLr) is a key mechanism to control elevated plasma LDL-cholesterol levels. Here we identify a new class of compounds that directly binds to the sterol regulatory element-binding protein (SREBP) cleavage-activating protein (SCAP). We show that a 14C-labeled, photo-activatable analog specifically labeled both SCAP and a truncated form of SCAP containing the sterol-sensing domain. When administered to hyperlipidemic hamsters, SCAP ligands reduced both LDL cholesterol and triglycerides levels by up to 80% with a three-fold increase in LDLr mRNA in the livers. Using human hepatoma cells, we show that these compounds act through the sterol-responsive element of the LDLr promoter and activate the SCAP/SREBP pathway, leading to increased LDLr expression and activity, even in presence of excess of sterols. These findings have led to the identification of a class of compounds that represent a promising new class of hypolipidemic drugs.

Animals↗
PubMed2001

A polymorphism in the endothelin-A receptor gene predicts survival in patients with idiopathic dilated cardiomyopathy.

AIMS: The endothelin system plays a role in the complex pathophysiology of idiopathic dilated cardiomyopathy. We investigated whether genetic polymorphisms of the endothelin system might be associated with dilated cardiomyopathy-related cardiac phenotypes and differences in disease outcome. METHODS: One hundred and twenty-five unrelated dilated cardiomyopathy patients of a well characterized dilated cardiomyopathy cohort were genotyped for six common polymorphisms of the endothelin-1, endothelin-A (ETA) and endothelin-B (ETB) receptor genes using hybridization with allele-specific oligonucleotides. RESULTS: The H323H (C/T) polymorphism in exon 6 of the ETA receptor gene was significantly associated with a shorter survival time after diagnosis. The odds ratio for carriers of the less frequent ET(A)T allele to die within 2 years after diagnosis was 5.5 (95% confidence interval, 1.4 to 21.0, P=0.013) compared to non-carriers. Kaplan-Meier analysis revealed a significantly different survival time for T allele carriers as compared to non-carriers as tested by logrank (P=0.0196), Breslow (P=0.0195), and Tarone tests (P=0.020). The influence of the ETA H323H polymorphism on survival remained significant when known predictors of prognosis such as left ventricular ejection fraction, left ventricular end-diastolic diameter, age and NYHA functional classification were entered in a Cox proportional hazards analysis. In this model, end-diastolic diameter showed a trend to influence survival (P=0.07) but only the ETA H323H polymorphism (P=0.0029) was a significant independent predictor of survival. CONCLUSIONS: Our results suggest that genetic variation in the ETA receptor predicts survival in dilated cardiomyopathy patients, which might have important consequences for the identification of high-risk individuals.

Adrenergic beta-Antagonists↗
PubMed1999

Investigation of a family with autosomal dominant dilated cardiomyopathy defines a novel locus on chromosome 2q14-q22.

Dilated cardiomyopathy (DCM) is a leading cause of heart failure and the most frequent indication for heart transplantation in young patients. Probably >25% of DCM cases are of familial etiology. We report here genetic localization in a three-generation German family with 12 affected individuals with autosomal dominant familial DCM characterized by ventricular dilatation, impaired systolic function, and conduction disease. After exclusion of known DCM loci, we performed a whole-genome screen and detected linkage of DCM to chromosome 2q14-q22. Investigation of only affected individuals defines a 24-cM interval between markers D2S2224 and D2S2324; when unaffected individuals are also included, the critical region decreases to 11 cM between markers D2S2224 and D2S112, with a peak LOD score of 3.73 at recombination fraction 0 at D2S2339. The identification of an additional locus for familial autosomal dominant DCM underlines the genetic heterogeneity and may assist in the elucidation of the causes of this disease.

Adolescent↗
PubMed1997

[Bourneville's tuberous sclerosis and autism].

Tuberous sclerosis is often associated with developmental and behavioural disorders including typical or partial autistic syndrome. However, it may be difficult to recognize tuberous sclerosis behind an infantile autism during the early stages of the disease. Therefore, tuberous sclerosis must be regularly looked for on the basis of its major and minor criteria in any cases of infantile autism. The child psychiatrist is preferentially involved in the management of the various aspects of this association, ie, behavioural or character disorders, difficulties in social relationships and communication, mental retardation, feeding disorders, and psychological consequences for the families. The support provided may be complemented by that offered by the Association for Bourneville's tuberous sclerosis.

Autistic Disorder↗
PubMed1997

Deafness and Mondini dysplasia in Kabuki (Niikawa-Kuroki) syndrome. Report of a case and review of the literature.

Report of a case and review of the literature: We report the case of a seven-year-old female kabuki patient suffering from severe bilateral deafness related to Mondini dysplasia and ossicular anomalies. A review of the literature in English confirms that hearing loss is a major component of Kabuki Syndrome (KS) with a frequency at around 32%. However the possible mechanisms have not been fully described and hearing loss is often attributed to otitis media, but one reported case had severe ossicular malformations, two had sensorineural deafness and three others had mixed deafness. Our observation is the first reported case of Mondini dysplasia in KS. Awareness by physicians of this problem has a major practical consequence as diagnosis of Mondini dysplasia implies searching for and surgical prevention and treatment of perilymphatic fistula in order to prevent meningitis.

Abnormalities, Multiple↗
PubMed1996

Serotonin and autism: biochemical and molecular biology features.

Whole blood and urinary levels of serotonin (5-hydroxytryptamine; 5-HT) and the derivative urinary 5-hydroxyindoleacetic acid (5-HIAA) were measured in normal and autistic subjects. An association was tested between autism and a marker coding for the 5-HT2A serotonergic receptor gene. Significant group (high urinary 5-HT and low whole blood 5-HT in autism) and age effects (urinary 5-HT decrease with age) were found. Moreover, whole blood 5-HT levels were correlated with clinical state. No differences in allele and genotype frequencies for the 5-HT2A receptor marker were found in this autistic population compared with age-matched healthy students.

Adolescent↗
PubMed1996

X chromosome and infantile autism.

Family studies and epidemiologic data in autism show the involvement of genetic factors in the etiology of this syndrome. The frequent association of X chromosome with mental retardation and behavior disturbances raises the question of its implication in the etiology of autism. Several markers of X chromosome were tested in autistic and control populations by association study. The autistic population was submitted to an extensive clinical examination. For the DXS287 marker, chi 2 analysis showed a different allele distribution between control and patient groups. This difference was enhanced when children with the most severe autistic behaviors and the least serious cognitive disorders were selected for statistical comparison. To our knowledge, this is the first association study described using markers of X chromosome in infantile autism. These preliminary results encourage our research on this chromosome, which could be considered as a significant genetic component of the multifactorial etiology of autism.

Adolescent↗
PubMed1996

Interregional equilibrium with heterogeneous labor.

"The impact of labor migration on interregional equilibrium is studied when workers are heterogeneous in productivity and regional mobility. The skilled respond to market disequilibrium by moving into the most attractive region. The unskilled are immobile in the short-run and move with the skilled in the long-run. Both regions have a neoclassical production function affected by an externality depending on the number of skilled. Workers move according to the utility differential when regional amenities vary with population or according to the wage differential. The equilibrium pattern depends on the unskilled's mobility and on migration incentives. Typically, regional imbalance characterizes the equilibrium which is often suboptimal."

Demography↗
PubMed1995

Autism and genetics: clinical approach and association study with two markers of HRAS gene.

Twin studies and familial aggregation studies indicate that genetic factors could play a role in infantile autism. In an earlier study, we identified a possible positive association between autism and a c-Harvey-ras (HRAS) oncogene marker at the 3' end of the coding region. In an attempt to confirm this finding, we studied a larger population, well-characterized clinically and genetically. We report a positive association between autism and two HRAS markers, the 3' marker used in the initial study and an additional marker in exon 1.

Adolescent↗
PubMed1995

Association study with two markers of a human homeogene in infantile autism.

Epidemiological data and family studies in autism show that there is a genetic susceptibility factor in the aetiology of this syndrome. We carried out an association study in infantile autism. Two markers of the homeogene EN2 involved in cerebellar development were tested in a population of 100 autistic children and in a population of 100 control children. With the MP4 probe showing a PvuII polymorphism, significant differences in the allele frequencies between the two populations were found (chi 2 = 7.99, df = 1, p < 0.01). With the MP5 probe showing an SstI polymorphism, no difference appeared (chi 2 = 1.17, not significant). Several clinical examinations allowed us to characterise the autistic children. Most of them had high scores for autistic behaviour and language disorders but low scores for neurological syndromes. Two children had a significant family history and six children had confirmed syndromes or diseases of genetic origin. Discriminant analysis between clinical and molecular data did not give significant results. These preliminary results must be supported by further analyses of this gene and by studies of its potential involvement in the pathophysiology of the autistic syndrome.

Adolescent↗