Submitted by David Rosenfield, MD, News Science Editorial Board
Edited by Francisco Gomez, MD, News Science Editorial Board
Recent years have seen a sharp increase in the discovery of biomarkers, physical measurable parameters linked to all points of the disease continuum. By all signs, the discovery of these elements will continue into the future with increasing pace. The questions of clinical implementation arise as the distance between practice and scientific discovery shortens.
Over the past several months, an ever increasing number of articles on this subject have been published. The AANEM News Science Editorial Board is striving to keep our readers abreast of these recent discoveries.
In “Rise of the Biomarkers – Part 1” (of a four-part series), we present new findings in the genetics of Amyotrophic Lateral Sclerosis (ALS). The article summary below outlines how genetic testing can provide new insights into the pathogenesis of Sporadic ALS, which may not be as sporadic as previously considered.
Additional article summaries on biomarkers will be forthcoming in subsequent AANEM publications.
Gibson, SB, Downie JM, Tsetsou A, et. al. The evolving genetic risk for sporadic ALS. Neurology 2017; 89: 226-233.
ALS is a progressive neurodegenerative disease of upper and lower motor neurons. This disease is classified as Familial ALS (FALS) when there is a clear family history of ALS and Sporadic ALS (SALS) when there is not. No clinical features reliably distinguish FALS from SALS. FALS represents 10% of ALS patients and follows an autosomal dominant inheritance pattern. The heritability of SALS, however, remained somewhat more nebulous. In this study, the authors sought to determine the SALS risk conferred by ALS associated genes.
Authors evaluated 87 SALS patients via whole genome repeat expansion focusing on variants in the 31 genes with known links to ALS, including the C9orf72 and ATXN2 genes.
The authors determined that 17% of their patients with SALS carried pathogenic genetic variants, of which were notable 5.7% had C9orf72 mutations, while SOD1 and ATXN2 both appeared in 2.3%.
Comment: Many patients with SALS will have a genetic component, and, more importantly, there may be asymptomatic carriers for the disease. This highlights that, in many instances, having the gene may be necessary but not sufficient for having ALS.
About the AANEM News Science Editorial Board:
The News Science Editorial Board (NSEB) reviews more than 30 medical journals to identify important, newsworthy items in the field and summarizes pertinent manuscripts to share with AANEM colleagues. The NSEB consists of 12 physicians from varied backgrounds (in training, attending, subspecialties [PMR or neuromuscular, adult or pediatric], practice settings [academic, research, or private practice], etc.).