Intracranial Volume Is Driven by Both Genetics and Early Life Exposures: The SOL-INCA-MRI Study.

Area of Science:

• Neuroscience
• Genetics
• Public Health

Background:

• Intracranial volume (ICV) is a key indicator of brain development and is linked to cognitive function later in life.
• Understanding factors influencing ICV is crucial for public health and cognitive aging research.

Purpose of the Study:

• To quantify ICV in Hispanic and Latino adults.
• To estimate ICV heritability and its genetic associations.
• To examine the impact of early life environmental factors on ICV.

Main Methods:

• Analysis of MRI data from 1781 unrelated individuals in the Study of Latinos-Investigation of Cognitive Aging - MRI (SOL-INCA-MRI).
• Estimation of ICV heritability.
• Testing associations with genetic variants and a genetic risk score (GRS).
• Assessment of environmental factors: nativity, age of immigration, and parental education.

Main Results:

• ICV heritability was estimated at 19%.
• Four genetic variants and the ICV-GRS were significantly associated with ICV.
• Immigration at age 11+ was linked to smaller ICV (-24 cm³).
• Higher parental education was associated with greater ICV (+15.4 cm³).

Conclusions:

• Genetic factors play a role in ICV, but environmental influences are also significant.
• Early life conditions, including immigration and parental education, impact brain development.
• These findings highlight the importance of early life health for cognitive aging.