What is the fine-grained topic of the following text: More recently, a genome-wide association study which included 20,000 human subjects was widely reported by the media to have discovered an “IQ gene.” According to their results, certain variations in the HMGA2 gene, which codes for a protein that helps regulate DNA transcription and cell growth, are correlated with increased intracranial volume as well as enhanced IQ. Only return the topic.
A Genome-Wide Association Study on the HMGA2 Gene's Influence on Intracranial Volume and IQ