Predicting haplotype carriers from SNP genotypes in Bos taurus through linear discriminant analysis

Area of Science:

• Animal Genetics
• Genomic Prediction
• Quantitative Genetics

Background:

• Single nucleotide polymorphism (SNP) genotype data are increasingly available in cattle.
• Accurate classification of individuals into haplotype carriers and non-carriers is crucial.
• A haplotype on BTA19 is associated with reduced cow fertility.

Purpose of the Study:

• To present a practical statistical method for accurate identification of haplotype carriers.
• To combine variable selection and linear discriminant analysis for carrier identification.
• To identify carriers of a fertility-associated haplotype on BTA19 in Brown Swiss cattle.

Main Methods:

• Variable selection to identify predictive SNPs.
• Linear discriminant analysis for classification.
• Analysis of 3645 Brown Swiss cattle genotyped with the 54K SNP-chip.

Main Results:

• The overall error rate for haplotype carrier prediction was very low (approximately ≤1%).
• Error rate depended on the number and density of SNPs around the BTA19 haplotype region.
• A minimum set of 5 SNPs achieved accurate predictions with a 1.59% total test error rate.

Conclusions:

• The described procedure accurately identifies haplotype carriers from SNP genotypes in cattle.
• The method demonstrated very few misclassifications, indicating high reliability.
• This approach has potential applications in cattle breeding for improved fertility.