The Sibship Index can't discriminates Half-Sibs from Full Sibs; a new algorithm, including maternal genotype, can do it [article]

Giuseppe Cardillo
2018 bioRxiv   pre-print
Sibship DNA testing is conducted in order to determine if two subjects share one or both biological parents in common: Full siblings have both parents in common, whereas Half siblings have one parent in common, either the mother or the father. When an alleged father is not available for a paternity test, sibship testing is one way to determine family relationships. Results of a sibship test have also been accepted as proof in Social Security benefit and other inheritance claims. To analyze the
more » ... ms. To analyze the possibility that the siblings share two common parents versus only one common parent, the ratio of the full sibship index versus half sibship index is computed: a sibship index less than 1, provides genetic evidence which does not favor a full-sibling relationship. In this paper we will demonstrate that the actually used Sibship Index is unable to distinguish Full-sibs from Half-Sibs and the only way to distinguish them is to use a new Index including the genotype of the Mother, that, usually, is the known common parent.
doi:10.1101/265561 fatcat:3sitvm6penbh7px3xlkxhldy4i