An unusual case of identification by DNA analysis of siblings

A badly decomposed body required identification by means of DNA analysis. A brother and sister of the deceased were available as reference subjects. Although investigation of Y-chromosomal markers established an exclusion condition, autosomal markers suggested a positive identification. In order to increase the reliability of the tests, X-chromosomal markers were also investigated. This analysis showed the body to have an XXY genotype (Klinefelter's syndrome). A number of hypotheses were assessed using biostatistical methods, ultimately resulting in a definite identification. The special aspect of Klinefelter's syndrome proved highly useful for biostatistical analysis.