“Intracranial volume reflects the maximally attained brain size during development, and remains stable with loss of tissue in late life. It is highly heritable, but the underlying genes remain largely undetermined. In a genome-wide association study of 32,438 adults, [Adams et al.] discovered five previously unknown loci for intracranial volume and confirmed two known signals. Four of the loci were also associated with adult human stature, but these remained associated with intracranial volume after adjusting for height.” A high genetic correlation with child head circumference was found, which indicates a similar genetic background and allowed identification of four additional loci. “Variants for intracranial volume were also related to childhood and adult cognitive function, and Parkinson’s disease, and were enriched near genes involved in growth pathways, including PI3K-AKT signaling. These findings identify the biological underpinnings of intracranial volume and their link to physiological and pathological traits.”
Adams HH, Hibar DP, Chouraki V, Stein JL, Nyquist PA, Renteria ME, Trompet S, Arias-Vasquez A, Seshadri S et al: Novel genetic loci underlying human intracranial volume identified through genome-wide association. Nature Neuroscience [Epub ahead of print, October 3, 2016; doi:10.1038/nn.4398].
Krabbe K et al.: Increased intracranial volume in Parkinson’s disease. J. Neurol. Sci. 239(1): 45-52 (2005).