[Neurodevelopmental (fragile X syndrome) and neurodegenerative (tremor/ataxia syndrome) disorders associated to the 'growth' of a gene]. / Trastornos del neurodesarrollo (síndrome X frágil) y neurodegenerativos (síndrome de temblor/ataxia) asociados al 'crecimiento' de un gen.

AIM: To present the latest findings on fragile X syndrome, the first genetic disorder identified to be caused by a new type of mutation called trinucleotide repeat expansion. DEVELOPMENT: Fragile X syndrome is the most common form of inherited mental retardation, is caused by hyperexpansion and hypermethylation of a CGG repeat tract in the FMR1 gene. In the first section we will discuss the various aspects of the gene mutation and the gene product, its phenotypic consequences in mutation carriers, diagnostic methodology, epidemiology, prevention, treatment and situation in Costa Rica. The second section deals with the recent findings in relation to the very recently described fragile X premutation tremor/ataxia syndrome, a neurodegenerative disorder affecting carriers of the mutation. CONCLUSIONS: Screening for the gene premutation in aged individuals who have tremor and balance problems is important, especially when accompanied by other signs such as parkinsonism, short term memory loss and dementia. Family genetic counselling can help those affected as well as future generations which may inherit fragile X syndrome.

[Molecular and genetic aspects of the myotonic conditions]. / Aspectos geneticos y moleculares de las enfermedades miotonicas.

AIM: The aim is to review the molecular and genetic aspects of the dystrophic and no dystrophic myotonias. BACKGROUND: Myotonic diseases are hereditary conditions of the skeletal muscle, classified in two groups depending on the symptoms. In the first group are the myotonic dystrophies, with the myotonic dystrophies type 1 and 2. In the second group are the channelopathies, characterized for the affected function of the ion channels. Myotonic dystrophy type 1, a neurodegenerative, progressive and disabling disease is caused by an expansion of the CTG trinucleotide, its size shows a positive correlation with the severity and negative with age of onset. There are enough insights to think that the gain of function of the mutant ARN is the pathophysiological mechanism occurring on this disease. Myotonic dystrophy type 2, less severe than type 1, is caused by an expansion of the CCTG tetranucleotide, its pathophysiological mechanism is similar to that one proposed for the type 1. In the second group we can find the chloride channelopathies, with autosomal dominant or recessive inheritance, caused by one of the 60 different mutations on the chloride channel gene; and the sodium channelopathies, group of three clinically overlapping diseases, with dominant heredity caused by one of the 25 different mutations on the sodium channel gene. CONCLUSIONS: These diseases are highly clinically variable, and even though their genetic base is known, it is necessary too much research in order to understand their pathophisiology and the phenotype genotype relationships.

[Intergenerational study of the mutation that causes Myotonic Dystrophy Type 1 in Costa Rica]. / Estudio intergeneracional de la mutación que causa la distrofia miotónica tipo 1 en Costa Rica.

INTRODUCTION: Myotonic dystrophy type 1 is a neuromuscular, degenerative and progressive disease, with an autosomal dominant pattern of inheritance, variable expressivity and incomplete penetrance. The genetic defect is an unstable mutation due to the expansion of the triplet CTG in the 3 unstranslated region at the DMPK gene on chromosome 19q13.3. OBJECTIVE: The main objective was to study the intergenerational behavior of the DM1 mutation in order to evaluate the importance of this disease as a neurological problem that could be manageable by genetic counseling. PATIENTS AND METHODS: The study involved 84 patients with clinical diagnosis of DM1 and their relatives, which were confirmed through molecular diagnosis using Southern blot and PCR. RESULTS: Data analysis reveals the size of the mutation presents a positive correlation with the severity of the symptoms and a negative correlation with the age of onset. Transmission of the DM1 mutation is sex and size dependent among the Costa Rican patients. There is an important increment in the size of the mutation between generations and there are no differences in mutation size respect to the transmitting sex. CONCLUSION: The worldwide intergenerational behavior of the DM1 mutation is similar in Costa Rica

Guías actualizadas de la ACC/AHA para evaluación cardiovascular perioperatoria para cirugía no cardiaca / Actualized guidelines of the ACC/AHA for perioperative cardiovascular evaluation to no cardiac surgery

Estas guías representan una actualización de aquellos publicados en 1996 dirigidas a médicos que están comprometidos en el cuidado preoperatorio, operatorio y postoperatorio de pacientes que van a cirugía no cardiaca. Ellas proveen un marco de referencia para analizar el riesgo cardiaco de cirugia no cardiaca en una variedad de pacientes y situaciones quirúrgicas. El tema principal de estas guías es que la intervención preoperatoria es raramene necesaria simplemente para disminuir el riesgo de la cirugía a menos que dicha intervención sea indicada independiente del contexto preoperatorio.

Colonoscopía: su rol actual en el dignóstico de enfermedades del colon / Colonoscopy: today role in diagnosis of colonic diseases

The preparation, medication, indications, methods, complications and results of colonoscopy for the diagnosis of colonic disease is presented

Torture sequelae located to the skin.

Torture sequelae and associated diagnostic problems within the field of dermatology are reported. Patient 1 claimed to have been subjected to torture in 1973 in South America and reported that he had a thick rubber-like rope tied around each thigh just above the knees. Six years later a linear zone of alopecia was observed extending circularly around each thigh, probably representing cicatricial alopecia. Patient 2 claimed to have been subjected to torture in November 1978 in Iraq and reported that he was burned on several areas of the skin with a metal rod of the size and shape of a cigarette. One year later, several circular or serpiginous scars with a markedly atrophic centre and a narrow hypertrophic, distinctly demarcated peripheral zone were observed on the skin. They probably represent the sequelae to deep third-degree burns produced by an electrically heated, cylindrical metal rod. Patient 3 claimed to have been subjected to torture in July and August 1974 in India. She reported to have been burned on several areas of the skin with a cigar as well as lifted by her hair. A few days after the torture she developed transient features typical of traction alopecia in the scalp, including the appearance of pimples. The examination 6 years later revealed on the extremities two irregularly shaped and indistinctly demarcated scars, one of them slightly atrophic, which might be sequelae to burns produced by an ember from a cigar.

Medical examination of torture victims applying for refugee status.

Torture is being increasingly reported. Canada provides a refuge for some of the victims. The medical evidence may be sufficient to give an applicant refugee status. Protocols are presented for the use of physicians in examining applicants for refugee status, and a series of cases is reported in which these protocols were followed.