Testing for modes of inheritance involving compound heterozygotes

Area of Science:

• Genetics
• Bioinformatics
• Genomic analysis

Background:

• Advances in sequencing technology enable cost-effective assaying of functional variants.
• Modeling the joint effects of functional variants is crucial for comprehensive analysis.
• Loss-of-function (LOF) mutations eliminate a gene's protein product, impacting phenotypes.

Purpose of the Study:

• To propose and evaluate methods for modeling the interaction of LOF mutations, considering their strand colocalization.
• To assess the impact of LOF mutations occurring on the same or different DNA strands/haplotypes.
• To compare the performance of novel methods against existing approaches for analyzing LOF variants.

Main Methods:

• Development of three novel methods to model LOF mutation interactions using strand colocalization information.
• Simulation studies comparing proposed methods with existing techniques, such as collapsed double heterozygosity.
• Analysis of both common and rare LOF variants to assess method performance across different allele frequencies.

Main Results:

• Two proposed methods demonstrated effective power profiles for analyzing LOF variants.
• One method showed desirable power for both common and rare LOF variants.
• The collapsed double heterozygosity method performed well for rare variants, particularly when haplotypes had limited rare alleles.

Conclusions:

• The proposed methods, especially those accounting for strand colocalization, offer improved analysis of functional variants.
• These methods are recommended for analyzing LOF variants identified through modern sequencing studies.
• Understanding LOF mutation interactions, including strand effects, is key to interpreting genetic variation and its phenotypic consequences.