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Antecedentes: Las mutaciones del gen GDAP1 son causantes de la enfermedad de Charcot Marie Tooth tanto autosomica dominante como recesiva, y se han reportado mas de 40 mutaciones distintas. La mutacion recesiva Q163X ha sido descrita en pacientes de ascendencia espanola y se ha demostrado una mutacion fundadora originaria de Espana en pacientes de origen suramericano. Describimos las caracteristicas fisicas e histologicas y el impacto molecular de la mutacion Q163X en una familia colombiana. Objetivo: Se describe el impacto de la mutacion Q163X en las caracteristicas fisicas, histologicas y moleculares en una familia colombiana. Metodos: Se describe dos pacientes de sexo femenino, hijas de padres consanguineos, quienes presentaron inicio de sintomas en los dos primeros anos de vida, mostrando deterioro funcional severo, sin evidencia de dismorfia, disfonia o paralisis diafragmatica . Los estudios de electrofisiologia mostraron una neuropatia sensitiva y motora con patron axonal. Se solicito la secuenciacion del gen GDAP1 , y el estudio identifico una mutacion homocigota puntual (c. 487 C>T) en el exon 4, causando un codon de parada prematuro (p. Q163X). Este resultado confirma el diagnostico de Enfermedad de Charcot Marie Tooth, tipo 4A (recesiva, tipo axonal). Resultados: Las pacientes fueron remitidas al servicio de Fisiatria para evaluacion de metodos de asistencia para deambulacion. Ellas reciben seguimiento por el servicio de Neumologia, quienes vigilan la funcion pulmonar y el desarrollo de paralisis diafragmatica. Se brindo asesoramiento genetico. La genealogia del paciente, las caracteristicas fenotipicas y los hallazgos en los estudios electrofisiologicos son herramientas valiosas en el enfoque clinico del paciente con CMT, de forma que se pueda plantear una posible mutacion causal. Se debe considerar la presencia de mutaciones en el gen GDAP1 en pacientes de origen suramericano, en especial la mutacion Q163X, como causa de CMT4A.

Mutations of GDAP1 gene cause autosomal dominant and autosomal recessive Charcot-Marie-Tooth disease and more than 40 different mutations have been reported. The recessive Q163X mutation has been described in patients of Spanish ancestry, and a founder mutation in South American patients, originating in Spain has been demonstrated.We describe physical and histological features, and the molecular impact of mutation Q163X in a Colombian family.We report two female patients, daughters of consanguineous parents, with onset of symptoms within the first two years of life, developing severe functional impairment, without evidence of dysmorphic features, hoarseness or diaphragmatic paralysis. Electrophysiology tests showed a sensory and motor neuropathy with axonal pattern. Sequencing of GDAP1 gene was requested and the study identified a homozygous point mutation (c.487 CT) in exon 4, resulting in a premature stop codon (p.Q163X). This result confirms the diagnosis of Charcot-Marie-Tooth disease, type 4A.The patients were referred to Physical Medicine and Rehabilitation service, in order to be evaluated for ambulation assistance. They have been followed by Pulmonology service, for pulmonary function assessment and diaphragmatic paralysis evaluation. Genetic counseling was offered. The study of the genealogy of the patient, phenotypic features, and electrophysiological findings must be included as valuable tools in the clinical approach of the patient with Charcot-Marie-Tooth disease, in order to define a causative mutation. In patients of South American origin, the presence of GDAP1 gene mutations should be considered, especially the Q163X mutation, as the cause of CMT4A disease.Las mutaciones del genSe describe el impacto de la mutación Q163X en las características físicas, histológicas y moleculares en una familia colombiana.Se describe dos pacientes de sexo femenino, hijas de padres consanguíneos, quienes presentaron inicio de síntomas en los dos primeros años de vida, mostrando deterioro funcional severo, sin evidencia de dismorfía, disfonía o parálisis diafragmáticaLas pacientes fueron remitidas al servicio de Fisiatría para evaluación de métodos de asistencia para deambulación. Ellas reciben seguimiento por el servicio de Neumología, quienes vigilan la función pulmonar y el desarrollo de parálisis diafragmática. Se brindó asesoramiento genético. La genealogía del paciente, las características fenotípicas y los hallazgos en los estudios electrofisiológicos son herramientas valiosas en el enfoque clínico del paciente con CMT, de forma que se pueda plantear una posible mutación causal. Se debe considerar la presencia de mutaciones en el gen

Introduction As numbers of transplant recipients and survival rates increase, the vulnerability of this population to several malignancies also rises. Non-melanoma skin cancer (NMSC) carries the highest rates of morbidity and mortality in this population. To avoid these malignancies, it is necessary to identify particular risk factors in transplant recipients and to follow preventive protocols. Methods The MEDLINE and EMBASE databases were reviewed using as keywords the medical subject headings (MeSH) “transplantation”, “skin neoplasm” and “prevention”. The search was limited to clinical trials, randomized clinical trials and case–control studies conducted during the previous 20 years. Results The most important risk factors for the development of NMSCs in the transplant recipient population are cumulative ultraviolet radiation exposure, use of immunosuppressive agents (especially azathioprine as a photosensitizing agent) and infections by human papillomaviruses. The use of sun protection and retinoids were identified as possible protective factors. Other potential therapies, such as antioxidants, difluormethylornithine and cyclooxygenase-2 inhibitors, require further study. Conclusions Patient risk factors for the development of NMSC should be reviewed during the transplant consultation. Individuals found to be at increased risk should undergo closer follow-up and preventive care counseling. This article proposes an algorithm for the prevention of NMSC.

INTRODUCTION. Epilepsy is a neurological disorder characterised by a predisposition to the recurrence of seizures of distinct causation and with variable clinical manifestations. Up to 40% of patients do not manage to control their seizures with the first anticonvulsive drug and the addition of a second pharmaceutical affords control in only another 11%. Given the aetiological heterogeneity of pharmacoresistance, it has been suggested that the presence of genomic disorders in patients with refractoriness could be elements worthy of analysis when it comes to estimating the alteration in the pharmacokinetic or pharmacodynamic profiles of these patients. AIM. To detect the presence of subtelomeric rearrangements in Colombian paediatric patients with refractory epilepsy. PATIENTS AND METHODS. The multiplex ligation-dependent probe amplification (MLPA) technique was used to evaluate the presence of cytogenetically non-visible chromosome aberrations in subtelomeric regions of 113 patients diagnosed with refractory epilepsy from three national referral centres in Colombia. RESULTS. Subtelomeric chromosome aberrations were detected in 0.9% of patients corresponding to a duplication of locus 3p26.3 in gene CHL1. CONCLUSIONS. This study suggests the use of the MLPA methodology to detect subtelomeric rearrangements that may be associated with phenotypes of refractoriness in epileptic patients.Deteccion de rearreglos subtelomericos por MLPA en pacientes pediatricos con epilepsia refractaria en Colombia: papel del gen CHL1 en la farmacorresistencia.Introduccion. La epilepsia es un trastorno neurologico caracterizado por una predisposicion a la recurrencia de crisis convulsivas de etiologia diversa y con manifestaciones clinicas variables. Hasta un 40% de los pacientes no logra el control de las crisis con el primer tratamiento anticonvulsionante y la adicion de un segundo farmaco logra el control de solo un 11% adicional. Dada la heterogeneidad etiologica de la farmacorresistencia se ha propuesto que la presencia de trastornos genomicos en pacientes con refractariedad podrian ser elementos de analisis a la hora de estimar la alteracion en los perfiles farmacocineticos o farmacodinamicos de estos pacientes. Objetivo. Detectar la presencia de rearreglos subtelomericos en pacientes pediatricos colombianos con epilepsia refractaria. Pacientes y metodos. Se utilizo la tecnica de amplificacion multiple de sondas dependiente de ligamiento (MLPA) para evaluar la presencia de aberraciones cromosomicas no visibles citogeneticamente en las regiones subtelomericas de 113 pacientes diagnosticados con epilepsia refractaria provenientes de tres centros de referencia nacional en Colombia. Resultados. Se detectaron aberraciones cromosomicas subtelomericas en el 0,9% de los pacientes correspondientes a una duplicacion del locus 3p26.3 en el gen CHL1. Conclusion. Este estudio plantea el uso de la metodologia de MLPA para la deteccion de rearreglos subtelomericos que puedan asociarse con fenotipos de refractariedad en pacientes epilepticos.

INTRODUCTION. Epilepsy is a neurological disorder characterised by a predisposition to the recurrence of seizures of distinct causation and with variable clinical manifestations. Up to 40% of patients do not manage to control their seizures with the first anticonvulsive drug and the addition of a second pharmaceutical affords control in only another 11%. Given the aetiological heterogeneity of pharmacoresistance, it has been suggested that the presence of genomic disorders in patients with refractoriness could be elements worthy of analysis when it comes to estimating the alteration in the pharmacokinetic or pharmacodynamic profiles of these patients. AIM. To detect the presence of subtelomeric rearrangements in Colombian paediatric patients with refractory epilepsy. PATIENTS AND METHODS. The multiplex ligation-dependent probe amplification (MLPA) technique was used to evaluate the presence of cytogenetically non-visible chromosome aberrations in subtelomeric regions of 113 patients diagnosed with refractory epilepsy from three national referral centres in Colombia. RESULTS. Subtelomeric chromosome aberrations were detected in 0.9% of patients corresponding to a duplication of locus 3p26.3 in gene CHL1. CONCLUSIONS. This study suggests the use of the MLPA methodology to detect subtelomeric rearrangements that may be associated with phenotypes of refractoriness in epileptic patients.