Determination of sibship by PCR-amplified short tandem repeat analysis in Taiwan

BACKGROUND: Sibship determination for any two persons whose parents have died is one of the most fundamental issues of personal identification, second only to those of a parent‐child relationship. STUDY DESIGN AND METHODS: By automated fluorescence analysis of a PCR‐amplified short tandem repeat (STR) system in conjunction with capillary electrophoresis, a panel of up to 15 polymorphic, autosomal, unlinked STR loci was used to investigate sibship index (SI) values in a cohort of 126 true sibling pairs. These SI values were then compared with those of 126 random pairs. RESULTS: The 15‐loci STR panel provides a cumulative power of exclusion of 0.9999997. Of the 126 random pairs, 124 (98.4%) had cumulative sibship indices (CSIs) of 3.0 (median, 0.0101; range, 0.0000003‐2.5376). In contrast, 107 (85%) of the 126 sibling pairs had a CSI of >100 (median, 5,579.9853; range, 0.0747‐9,406,829,249.8461). However, five pairs (4%) of the sibling group had a CSI of