Motor development is a central feature in the first two years of life. Gross motor milestones include learning to walk independently, while fine motor milestones include learning to stack small blocks. Once a motor milestone is reached, it triggers developmental cascades in areas such as social understanding and communication. Strong links have been observed between motor development and autism, including in the SPARK cohort1,2.
Significant variability is common in motor development in the population and gross motor development shows significant heritability3. Motor milestones also elicit changes in the child’s environment and niche construction through, for example, changes in posture, mobility and height. Physical health is also relevant: for example, some evidence suggests high body mass index is associated with delayed gross motor milestones4. For pediatricians, motor milestones are key for signaling delay. Developmental delay is seen in neurological disorders that affect the motor system, such as cerebral palsy, in learning disabilities and in neurodevelopmental disorders.
Despite the importance of motor development, very little is currently known about the role of genetic influences on this fundamental behavioral domain. To address this gap in the literature, Angelica Ronald and Mark Johnson plan to conduct a novel gene discovery project investigating common genetic variation on infant fine and gross motor development in the context of typical neurodevelopment. A range of large (all with n>1,000) developmental cohorts are being employed. The team will then examine genetic associations between motor development and autism using an array of state-of-the-art genetic analytic tools. Importantly, they will assess the degree of specificity of any genetic association between motor development and autism by employing multivariate modelling techniques and couching the analyses within the context of the broader domains of cognition and mental and physical health.
In sum, the project aims to understand the role of infant fine and gross motor development in relation to autism pathways using common genetic variation. Their proposed project is aligned with SFARI’s scientific perspectives: it is “grounded in biology” and aims to make insights “from genes to…behavior”.