The missing heritability of behavior: the search continues

Area of Science:

• Behavioral genetics
• Quantitative genetics
• Genomics

Background:

• The search for genetic underpinnings of behavioral variation has been hindered by the challenge of identifying specific genes.
• The concept of "missing heritability" highlights the gap between estimated genetic influence and identified genetic variants.
• Twin and family studies are crucial for dissecting the genetic and environmental contributions to complex traits.

Purpose of the Study:

• To discuss the implications of recent studies from the Minnesota Center for Twin and Family Research (MCTFR) for understanding genetic variation in behavior.
• To explore potential explanations for the limited success in identifying genes associated with behavioral traits.
• To propose future directions for genetic research on behavior.

Main Methods:

• Longitudinal measurement of endophenotypes in a twin cohort.
• Heritability analysis of behavioral traits.
• Genome-wide association studies (GWAS) and whole-genome sequencing for genetic mapping.

Main Results:

• Identified genes explain only a portion of the heritability for the studied behavioral traits.
• The study design and data suggest methodological limitations are not the sole reason for the "missing heritability".
• The MCTFR dataset represents a valuable resource for future genetic discoveries.

Conclusions:

• Future gene discoveries will likely emerge from novel analytical approaches and data integration across studies.
• Increasing sample sizes may be necessary to detect smaller genetic effects.
• Investigating families and population isolates with founder effects could aid in identifying rare alleles and specific genetic loci.