Expansión anormal de hexanucleótido en gen C9orf72 en una familia con demencia frontotemporal y cuadros asociados / Abnormal expansion of C9orf72 gene in familial frontotemporal dementia

Frontotemporal Dementia (FTD) and Motor Neuron Disease (MND) may share similar pathogenic mechanisms. An abnormal hexanucleotide expansion in C9orf72 gene is the most common genetic abnormality of these conditions and explains their concurrence in the same family. We report a 77-year-old female presenting with non-fluent aphasia leading to mutism and a mild Parkinsonism. A magnetic resonance imaging showed a severe atrophy of frontal and temporal lobes. Several family members of the patient suffered of atypical Parkinsonism, lateral amyotrophic sclerosis and dementia. We identified an abnormal hexanucleotide expansion in the C9orf72 gene in the proband. To the extent of our knowledge, this is the first time that this diagnosis is confirmed in our country. The knowledge of the genetic basis of neuro degenerative disorders improves diagnosis and opens expectatives for future treatments of these disabling conditions.

Manifestaciones neuropsiquiátricas y cognitivas en demencia frontotemporal y esclerosis lateral amiotrófica: dos polos de una entidad común / Overlapping features of frontotemporal dementia and amyotrophic lateral sclerosis

Recent genetic and neuropathologic advances support the concept that frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) are overlapping multisystem disorders. While 10-15% of ALS patients fulfil criteria for FTD, features of motor neuron disease appear in approximately 15% of FTD patients, during the evolution of the disease. This overlap has been reinforced by the discovery of Transactive Response DNA Binding Protein 43 kDa (TDP43) inclusions as the main neuropathologic finding in the majority of ALS cases and almost a half of FTD cases. Also, an expansion in the intron of C9ORF72 (chromosome 9p21) has been identified in families affected by ALS, ALS-FTD and FTD. This review provides an update on the recent genetic and neuropathologic findings of ALS and FTD and a characterization of their clinical presentation forms, based on the current diagnostic criteria. Finally it underscores the importance of having a national registry of patients with ALS and FTD, to provide an earlier diagnosis and a multidisciplinary care.