title: Hypothesis: higher prenatal testosterone predisposes ALS patients to improved athletic performance and manual professions.
abstract: Our objective was to propose a testable hypothesis arising from the recent finding of a low index-to-ring finger ratio (2D:4D ratio) in ALS. The 2D:4D ratio finding suggests that prenatal testosterone exposure may play a role in the development of the disease. Research from other fields is presented to suggest that healthy individuals with low 2D:4D ratio have enhanced sporting prowess, particularly with regard to activities requiring endurance and dependent upon slow-twitch muscles. Although studies are of varying quality, some epidemiological findings in ALS also suggest enhanced sporting prowess, as well as a higher risk of developing the disease among members of certain physically active professions. If the 2D:4D finding survives replication then this might explain the reported elevated risk of ALS among professional athletes, the military, and manual professions. Such a relationship might also explain why ALS patients were more likely to have been elite sportspeople in younger life. This hypothesis may serve as a starting point for debate and discussion over the nature of ALS risk factors, as well as generating a number of specific testable hypotheses that may yield insight into the genesis of the disease.
authors.affiliation: PatientsLikeMe, Research & Development, Cambridge, Massachusetts 02141, USA. pwicks@patientslikeme.com
authors.forename: Paul
authors.initials: P
authors.lastname: Wicks
mesh_terms: D000690:Amyotrophic Lateral Sclerosis / Q000209:etiology / Q000503:physiopathology*; D054874:Athletic Performance / Q000502:physiology*; D005260:Female; D005385:Fingers / Q000033:anatomy & histology*; D006801:Humans; D008297:Male; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000378:metabolism*; D012307:Risk Factors; D013739:Testosterone / Q000009:adverse effects*
chemical_list: D013739:Testosterone