ABSTRACT
La ataxia de Friedreich, de herencia autosómica recesiva causada por una expansión repetida de trinucleótidos se asocia, entre otras complicaciones sistémicas, con diabetes mellitus. La aparición de torpeza motriz, con dificultad en la carrera y el salto en un varón de 6 años motivaron el estudio genético para ataxia de Friedrich y permitieron confirmar el diagnóstico. Tres años más tarde, se diagnosticó diabetes mellitus y se inició el tratamiento con insulina. Durante el seguimiento, presentó un importante deterioro neurológico, con necesidad de usar silla de ruedas, lo que dificultó un adecuado control metabólico. Se presenta el manejo y la evolución de un paciente con ataxia de Friedreich y diabetes mellitus
Friedreich's ataxia is an autosomal recessive disease caused by trinucleotide repeat expansion, presenting among other systemic complications, diabetes mellitus. The appearance of motor clumsiness, with running and jumping difficulties in a 6-year-old boy prompted the genetic study of Friedreich's ataxia, confirming his diagnosis. After diagnosis,it was evaluated by Pediatric Cardiology, detecting the presence of non-obstructive hypertrophic cardiomyopathy, and by Pediatric Endocrinology, due to overweight. At 9 years of age, he was diagnosed with diabetes mellitus, a regimen of insulin treatment was initiated. During follow-up, he presented significant neurological deterioration, reaching the use of a wheelchair,which hinders adequate metabolic control. This is a report of a pediatric patient with Friedrich ataxia and diabetes mellitus.
Subject(s)
Humans , Male , Child , Friedreich Ataxia/complications , Friedreich Ataxia/diagnosis , Friedreich Ataxia/genetics , Diabetes Mellitus , Insulins , FamilyABSTRACT
La ataxia de Friedreich (AF) es la ataxia hereditaria más común; está causada por una expansión anormal del triplete GAA del primer intrón del gen X25 en el cromosoma 9. Se presenta comúnmente en menores de 25 años y se asocia a trastornos musculoesqueléticos, endocrinos y miocárdicos. Entre sus variantes fenotípicas se describen casos que inician su sintomatología después de los 25 años de edad, definidos como ataxia de Freidreich de inicio tardío (AFIT). Nuestro objetivo fue la descripción de una familia con tres hermanos afectados, todos de inicio tardío. Los síntomas se iniciaron entre los 32 y 34 años, con trastornos de la marcha y disartria cerebelosa, que se agravaron en el curso de 6 a 12 meses, haciéndose más evidentes. Ninguno presentaba compromiso musculoesquelético ni miocárdico. No existían antecedentes familiares de ataxias u otros trastornos neurológicos. En 2 casos se realizó estudio genético que evidenció la expansión anormal del triplete GAA, confirmando el diagnóstico de AF. Se realizaron resonancias magnéticas (RM) de encéfalo, encontrándose atrofia medular con preservación de estructuras cerebelosas en dos casos, y atrofia vermiana y medular en el tercero. En las ataxias cerebelosas con disartria y pérdida de la sensibilidad profunda que se inician después de los 25 años, sean éstas esporádicas o vinculadas a una herencia recesiva, se debe considerar la investigación de expansiones GAA en el gen de la AF.
Friedreich Ataxia (FA) is the most common hereditary ataxia, caused by abnormal expansion of the GAA triplet of the first intron of the X25 gene on chromosome 9. Clinically it occurs in patients under the age of 25 and it is frequently associated with musculoskeletal, endocrine and myocardial disorders. Among their phenotypic variants there are patients starting their symptoms after the age of 25. The latter group is defined as late onset Freidreich ataxia (LOFA). The objective of this work is to present three siblings affected by late onset Friedreich ataxia. Their symptoms began between the ages of 32 and 34, with gait disturbance and dysarthria of cerebellar type, which worsened, thus becoming more evident in the course of 6-12 months. None had musculoskeletal or myocardial involvement. There was no family history of ataxia or other neurological disorders. Two of these patients underwent genetic study that showed abnormal expansion of GAA triplet confirming the diagnosis of FA. A magnetic resonance imaging (MRI) of the brain was performed. Proximal spinal cord atrophy, sparing cerebellar structures, was found in two of the cases and vermian atrophy associated with proximal spinal cord atrophy was observed in the third one. Molecular testing GAA expansions in the FA gene should be considered in cerebellar ataxia with dysarthria and loss of proprioception.
Subject(s)
Female , Humans , Male , Middle Aged , Friedreich Ataxia/genetics , Age of Onset , Disease Progression , Friedreich Ataxia/diagnosis , Friedreich Ataxia/physiopathology , Magnetic Resonance Imaging , Pedigree , PhenotypeABSTRACT
Friedreich ataxia (FRDA), the most commom autosomal recessive ataxia, is caused in 94 per cent of cases by homozygous expansions of an unstable GAA repeat localised in intron 1 of the X25 gene. We have investigated this mutation in five Brazilian patients: four with typical FRDA findings and one patient with atypical manifestations, who was considered to have some other form of cerebellar ataxia with retained reflexes. The GAA expansion was detected in all these patients. The confirmation of FRDA diagnosis in the atypical case may be pointing out, as in other reports, that clinical spectrum of Friedreich's ataxia is broader than previously recognised and includes cases with intact tendon reflexes.