(HealthDay News) – Risk models that take gene-gene and gene-environment interactions into account only slightly improve the prediction of risk for three complex diseases.

Hugues Aschard, PhD, from the Harvard School of Public Health in Boston, and colleagues performed simulations to determine whether including multiple gene-gene and gene-environment interactions would affect the prediction of disease risk for breast cancer, type 2 diabetes, and rheumatoid arthritis. The improvement in discriminative ability was assessed using the difference in the area under the receiver operating characteristic curve (AUC).

The researchers found that, on inclusion of two to 10 gene-gene and gene-environment effects in the risk models, the improvement in discriminative ability was 2.82% for breast cancer, 1.40% for rheumatoid arthritis, and 0.85% for type 2 diabetes. There was an increase in the improvement of the AUC with increasing interaction effect, with the magnitude differing by disease.

“This study suggests that the identification of statistical interactions among these factors might have a modest impact on risk prediction and discrimination for common complex diseases,” the authors write. “We stress that although gene-gene and gene-environment interactions might have modest impacts on risk prediction, an understanding of the interplay between genes and the environment can provide insights into disease etiology; this understanding, in turn, can lead to improved treatment and prevention strategies.

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