The role of historical medical archives in the genealogical rebuilding of large families affected by neurodegenerative diseases

Abstract

Starting from a proband for whom a family history of neurodegenerative disorder has been reported, clinical and genealogical methods are often used together to reconstruct the pedigree of many large families affected by hereditary diseases. This approach was fundamental in the rebuilding of the N family, the kindred originated from southern Italy affected by early onset autosomal dominant Alzheimer’s disease (AD), that has given an important contribution to the discovery of Presenilin 1, the main gene responsible for AD. The identification of several patients in this pedigree, encompassing 11 generations with several hundred of affected subjects, was achieved through the meticulous study of medical records in the archives of the Provincial Psychiatric Hospital of Girifalco in Italy and in the municipal and parish archives of many towns belonging to the same geographical area. The research on N family triggered several other studies on hereditary neurodegenerative disorders in Southern Italy. Investigation focusing on antique archives and the analysis of phenotypes allowed to reconstruct and clinically detail large pedigrees of hereditary diseases, such as frontotemporal dementia and spinocerebellar ataxia 17, even before the discovery of their causative genes.