DNA databases are widely used in forensic science to identify unknown offenders. When no exact match is found, familial DNA searches can help by identifying first-degree relatives using likelihood ratios. If multiple subpopulations are relevant, likelihood ratios can be computed separately based on allele frequency estimates. Various strategies exist to combine these ratios, such as averaging allele frequencies or taking the average, maximum, or minimum likelihood ratio. While some comparisons have been made in populations like those in the U.S., their effectiveness in other regions remains unclear. This study evaluates likelihood ratio-based strategies in Southeast Asian populations, specifically Thailand, Malaysia, and Singapore. Our findings align with previous research, showing that statistical power varies across strategies. Among Thai subpopulations, the minimum likelihood ratio strategy is preferred, as it maintains high power while minimizing differences between subpopulations.

翻译：DNA数据库在法医学中被广泛用于识别未知犯罪者。当无法找到完全匹配时，家族DNA搜索可通过似然比识别一级亲属。若涉及多个亚群，可基于等位基因频率估计分别计算似然比。存在多种策略来合并这些比值，例如平均等位基因频率或取似然比的平均值、最大值或最小值。尽管已在美国等地区的人群中进行过一些比较，但这些策略在其他地区的有效性尚不明确。本研究评估了基于似然比的策略在东南亚人群（特别是泰国、马来西亚和新加坡）中的应用效果。我们的发现与先前研究一致，表明不同策略的统计功效存在差异。在泰国亚群中，最小似然比策略更受青睐，因其在保持高功效的同时最小化了亚群间的差异。