Measuring Concordance of Sulcogyral Patterns in Monozygotic and Dizygotic Twin Pairs
Author:
Shane Kozick ’23Co-Authors:
Marissa Patti, Will Snyder, Donielle Beiler, Vanessa TroianiFaculty Mentor(s):
Vanessa Troiani, Neuroscience (ADMI)Funding Source:
H Royer Undergraduate Research FundAbstract
The brain’s surface is made up of sulci (grooves) and gyri (ridges) that together create the distinct folded (sulcogyral) appearance of the brain. Sulcogyral folding patterns have been identified in the orbitofrontal cortex (OFC) based on the continuity of the medial and lateral orbital sulci (MOS & LOS). Pattern types are named according to their frequency in the neurotypical population, with Type I present in ~50%, Type II in ~30%, Type III in ~15%, and Type IV in ~5%. It has been previously found that populations with schizophrenia have reduced frequency of Type I patterns, but the heritability of the OFC sulcogyral patterns is unknown.
The goal of this project was to explore whether OFC patterns are heritable. We examined whether there is increased concordance of patterns in 172 monozygotic (MZ) twins relative to 304 dizygotic (DZ) twins using structural magnetic resonance imaging data. We also characterized pattern subtypes to explore variance within OFC sulci that is not based on MOS and LOS continuity.
We find no difference in concordance rates between MZ and DZ twin pairs. Results from subtype analysis suggest that variability exists in other sulci that are not captured in overall OFC pattern characterization. This suggests subtyping may be important for future studies to further understand the relationships between pattern types and subtypes. Overall, these results suggest minimal genetic influence on OFC pattern types, indicating that OFC sulcogyral patterns may capture important variance that is not genetic in origin but is relevant to psychiatric disease risk.