IBDelphi

IBDelphi showing regions of IBD across the autosomal genome

The IBDelphi algorithm is a method for identifying segments of IBD between two individuals. Using this knowledge it is possible to calculate the coefficients of inbreeding and relationships, as well as the probability of one of their children suffering from an autosomal recessive disease, assuming their common ancestor is heterozygous for a deleterious mutation.

The IBDelphi algorithm has been implemented in two software packages IBDelphi and IBDpopluations:

IBDelphi allows the analysis of Affymetrix high density SNP data from a consanguineous couple, or a consanguineous couple plus a relative affected by a possibly autosomal recessive disease, or a consanguineous couple plus a relative couple who had a child affected by a possibly autosomal recessive disease. When analysing data from a couple and an affected relative with a unknown mutation it is possible to compare the haplotype of the IBD regions in the couple to the haplotype of the autozygous regions in the affected relative. Using this knowledge it is possible to calculate the probability of one of their children suffering from the same autosomal recessive disease.

IBDpopulations analyses multiple Affymetrix high density SNP data file from one or two distinct population groups, estimating the degree of IDB between pairs of individuals, allowing the level intra population or inter-population relatedness to be calculated.

Feature guide

A “walk-through” explanation, with screenshots, of IBDelphi usage:

HTML guide

A “walk-through” explanation, with screenshots, of IBDpopulations usage:

HTML guide

Download

The download page currently offers a preview versions of both IBDelphi and IBDpopulations as well as some sample data files, used in the examples shown in the online Guides.

The IBDelphi and IBDpopulations programs have been written by Ian Carr. It is still undergoing testing, and any feedback on its features or performance would be very welcome.

 

Citation

Carr IM, Markham AF, Pena SDJ. Estimating the degree of identity by descent in consanguineous couples.
Hum Mutat. 2011 Dec;32(12):1350-8.