Abstract
We presented a risk assessment model to distinguish between type 1 diabetes (T1D) affected and unaffected siblings using only three single nucleotide polymorphism (SNP) genotypes. In addition we calculated the heritability from genome-wide identity-by-descent (IBD) sharing between full siblings. We analyzed 1,253 pairs of affected individuals and their unaffected siblings (750 pairs from a discovery set and 503 pairs from a validation set) from the T1D Genetics Consortium (T1DGC), applying a logistic regression to analyze the area under the receiver operator characteristic (ROC) curve (AUC). To calculate the heritability of T1D we used the Haseman-Elston regression analysis of the squared difference between the phenotypes of the pairs of siblings on the estimate of their genome-wide IBD proportion. The model with only 3 SNPs achieving an AUC of 0.75 in both datasets outperformed the model using the presence of the high-risk DR3/4 HLA genotype, namely AUC of 0.60. The heritability on the liability scale of T1D was approximately from 0.53 to 0.92, close to the results obtained from twin studies, ranging from 0.4 to 0.88.
Highlights
One of the main reasons for disease gene identification is to provide the ability to identify people who are at risk of disease
type 1 diabetes (T1D) is a major chronic childhood disease caused by a combination of genetic and environmental influences and genome wide association studies (GWAS) have found over 60 genes to affect the risk of the disease, with the HLA loci having the greatest impact on susceptibility
A subject was labelled as affected if the subject had documented T1D with onset at 37 years old, had used insulin within 6 months of diagnosis, and had no concomitant disease or disorder associated with diabetes
Summary
One of the main reasons for disease gene identification is to provide the ability to identify people who are at risk of disease. Even markers with replicated highly significant odds ratios may be poor classifiers and most variants identified so far confer only small increments in risk and still explain only a small proportion of phenotypic diversity [1]. T1D is a major chronic childhood disease caused by a combination of genetic and environmental influences and genome wide association studies (GWAS) have found over 60 genes to affect the risk of the disease, with the HLA loci having the greatest impact on susceptibility (reviewed in [2, 3]). The AUC for risk prediction using multiple identified variants ranges from 0.65 to 0.68 for T1D The AUC for risk prediction using multiple identified variants ranges from 0.65 to 0.68 for T1D (see ref. [4] for more details) despite the fact that T1D has a very strong family component with a heritability estimate from 0.4 to 0.8 [5,6,7,8].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
