Methods of selecting individuals having or predicted to develop abnormalities in brain volume, that may include microcephaly, or macrocephaly, and may manifest in neurological disorders such as schizophrenia or autism. Methods of selecting individuals having or predicted to develop low or high cognitive function, such as low or high IQ. Therapeutic methods of delivering DUF1220 domain protein products or fragments or mimetics thereof to enhance cognition in an individual, including patients with cognitive disorders, dementia, neurodegenerative disorders, and the like.
