Lack of replication for the myosin- 18B association with mathematical ability in independent cohorts.

Twin studies indicate that dyscalculia (or mathematical disability) is caused partly by a genetic component, which is yet to be understood at the molecular level. Recently, a coding variant (rs133885) in the myosin- 18B gene was shown to be associated with mathematical abilities with a specific effect among children with dyslexia. This association represents one of the most significant genetic associations reported to date for mathematical abilities and the only one reaching genome-wide statistical significance. We conducted a replication study in different cohorts to assess the effect of rs133885 maths-related measures. The study was conducted primarily using the Avon Longitudinal Study of Parents and Children ( ALSPAC), ( N = 3819). We tested additional cohorts including the York Cohort, the Specific Language Impairment Consortium ( SLIC) cohort and the Raine Cohort, and stratified them for a definition of dyslexia whenever possible. We did not observe any associations between rs133885 in myosin- 18B and mathematical abilities among individuals with dyslexia or in the general population. Our results suggest that the myosin- 18B variant is unlikely to be a main factor contributing to mathematical abilities. [ABSTRACT FROM AUTHOR]