Henshall John M, Tier Bruce
CSIRO Livestock Industries, J. M. Rendel Laboratory, Rockhampton, QLD, Australia.
Genet Res. 2003 Jun;81(3):205-12. doi: 10.1017/s0016672303006232.
No exact method for determining genotypic and identity-by-descent probabilities is available for large complex pedigrees. Approximate methods for such pedigrees cannot be guaranteed to be unbiased. A new method is proposed that uses the Metropolis-Hastings algorithm to sample a Markov chain of descent graphs which fit the pedigree and known genotypes. Unknown genotypes are determined from each descent graph. Genotypic probabilities are estimated as their means. The algorithm is shown to be unbiased for small complex pedigrees and feasible and consistent for moderately large complex pedigrees.
对于大型复杂家系，目前尚无确定基因型和同源概率的精确方法。此类家系的近似方法无法保证无偏差。本文提出了一种新方法，该方法使用Metropolis-Hastings算法对符合家系和已知基因型的系谱图马尔可夫链进行采样。从每个系谱图中确定未知基因型。基因型概率以其均值进行估计。结果表明，该算法对于小型复杂家系是无偏差的，对于中等规模的复杂家系是可行且一致的。
