Subject(s)
Hypotension, Orthostatic/complications , Migraine Disorders/etiology , Postural Orthostatic Tachycardia Syndrome/complications , Syncope/complications , Adult , Case-Control Studies , DNA, Mitochondrial/genetics , Female , Humans , Hypotension, Orthostatic/genetics , Hypotension, Orthostatic/physiopathology , Male , Migraine Disorders/genetics , Migraine Disorders/physiopathology , Point Mutation/genetics , Polymerase Chain Reaction , Polymorphism, Restriction Fragment Length , Postural Orthostatic Tachycardia Syndrome/genetics , Postural Orthostatic Tachycardia Syndrome/physiopathology , Syncope/genetics , Syncope/physiopathology , Syndrome , Young AdultSubject(s)
Adult , Female , Humans , Male , Young Adult , Hypotension, Orthostatic/complications , Migraine Disorders/etiology , Postural Orthostatic Tachycardia Syndrome/complications , Syncope/complications , Case-Control Studies , DNA, Mitochondrial/genetics , Hypotension, Orthostatic/genetics , Hypotension, Orthostatic/physiopathology , Migraine Disorders/genetics , Migraine Disorders/physiopathology , Polymerase Chain Reaction , Polymorphism, Restriction Fragment Length , Point Mutation/genetics , Postural Orthostatic Tachycardia Syndrome/genetics , Postural Orthostatic Tachycardia Syndrome/physiopathology , Syndrome , Syncope/genetics , Syncope/physiopathology , Young AdultABSTRACT
AIMS: To investigate the association of the Gly389 allele with positive head-up tilt test (HUT) in a Mexican Mestizo population. METHODS AND RESULTS: HUT results were compared between carriers (one or two copies of the Gly389 allele) and non-carriers (Arg389Arg genotype) of the Gly389 allele of the beta(1)AR gene in 50 patients with unexplained syncope. Thirty-three patients (66%) had a positive HUT. Patients with a positive HUT had a higher Gly389 allele frequency compared with those with a negative test (30.3 vs. 3%; OR 13; pC = 0.012). Moreover, when comparing positive HUT in passive drug-free phase, positive HUT in pharmacological (nitrate) phase, and negative (both phases), a decreasing gradient in the frequencies of the Gly389 allele was found among the three groups: 45.4, 22.7, and 3%, respectively. CONCLUSION: An association of positive tilt table testing to a single nucleotide polymorphism with a Gly to Arg switch at position 389 of the beta(1)AR was found. This polymorphism may contribute to susceptibility to faint during orthostatic challenge.
Subject(s)
Polymorphism, Single Nucleotide/genetics , Receptors, Adrenergic, beta-1/genetics , Syncope/epidemiology , Syncope/genetics , Tilt-Table Test/statistics & numerical data , Adult , Female , Genetic Predisposition to Disease/epidemiology , Genetic Predisposition to Disease/genetics , Heterozygote , Humans , Male , Mexico/epidemiology , Mutation , Syncope/diagnosisABSTRACT
The Brugada syndrome is an arrhythmic syndrome characterized by a right bundle branch block pattern and an segment elevation in the right precordial leads of the electrocardiogram, in conjunction with a high incidence of sudden death secondary to ventricular tachyarrhythmias. No evidence of structural heart disease is noted during diagnostic evaluation of these patients. The prognosis is poor with up to a 10 per year mortality. Antiarrhythmic drugs have no benefit in prolonging survival. The treatment of choice is the insertion of an implantable cardioverter defibrillator.
Subject(s)
Electrocardiography , Heart Block/physiopathology , Syncope/physiopathology , Death, Sudden , Heart Block/diagnosis , Heart Block/epidemiology , Heart Block/genetics , Heart Block/therapy , Humans , Prognosis , Syncope/diagnosis , Syncope/epidemiology , Syncope/genetics , Syncope/therapy , SyndromeABSTRACT
We present a patient with a complete Coffin-Lowry syndrome, associated with drop episodes precipitated by sudden auditory stimuli, which provoked in turn, a definite loss of muscle tone in both legs. Electrophysiological studies showed that these episodes are an unusual type of startle response and that they may be associated with Coffin-Lowry syndrome.
Subject(s)
Acoustic Stimulation/adverse effects , Craniofacial Abnormalities/genetics , Epilepsy, Reflex/genetics , Reflex, Startle/genetics , Sex Chromosome Aberrations/genetics , Syncope/genetics , X Chromosome , Adolescent , Craniofacial Abnormalities/diagnosis , Craniofacial Abnormalities/physiopathology , Diagnosis, Differential , Electroencephalography , Electromyography , Epilepsy, Reflex/diagnosis , Epilepsy, Reflex/physiopathology , Genes, Dominant/genetics , Humans , Male , Reflex, Startle/physiology , Syncope/diagnosis , Syncope/physiopathology , SyndromeABSTRACT
Andersen syndrome is a rare entity and comprises potassium sensitive periodic paralysis, ventricular arrhythmia, and an unusual facial appearance; syncope and sudden death have also been reported. The recognition of the characteristic face permits an early diagnosis in order to detect the severe systemic manifestations that are associated with this syndrome. The genetic defect is not linked to any other form of potassium sensitive periodic paralysis nor is it related to that of the long QT syndrome; nevertheless, a prolonged QT interval can be detected in a significant proportion of the cases. Sixteen cases of this syndrome have been described. We report on a three-generation family with 10 affected members. To our knowledge, this is the largest number of cases reported in one family. We noted some additional minor anomalies such as broad forehead and malar hypoplasia. Our patients had variable expression in the classical triad and of the severity of the systemic manifestations. Five of 8 affected studied members did not have a long QTc, which has been suggested as a constant finding in this syndrome.