One person with two DNA profiles: a(nother) case of mosaicism or chimerism

Abstract

Nuclear DNA markers, such as short tandem repeats (STR), are widely used for crime investigation and paternity testing. STR were used to determine whether a piece of tissue regurgitated by a dog was part of the penis of a dead, emasculated, man. Unexpectedly, when analyzing the recovered material and a blood sample from the deceased, five out of the 18 loci differed. According to the results, one could have concluded that these samples originated from two different persons. However, taking into account contextual information and data from complementary genetic analyses, the most likely hypothesis was that the deceased was a genetic mosaic or a chimera. Within a forensic genetic context, such genetic peculiarities may prevent associating the perpetrator of an offense with a stain left at a crime scene or lead to false paternity exclusions. Fast recognition of mosaics or chimeras, adapted sampling scheme, as well as careful interpretation of the data should allow avoiding such pitfalls.

An unusual observation of tetragametic chimerism: forensic aspects

“…For instance, three or four alleles at a locus could be indicative of two or more contributors. Consequently, without knowing the circumstances surrounding the case, the subsequent interpretation will be conditioned only on the STR analysis assumptions and could lead to false conclusions [12]. Molecular studies of chimerism on different tissues should be considered in such cases because many mosaic cell lines could be found to be chimeric if adequately tested.…”

Genetic insight into Nigerian population groups using an X-chromosome decaplex system

“…DNA can be collected from any biological material, like for example, blood, semen, hair, bones, skin and saliva, being the same regardless of the cell types that are used. There are some rare exceptions, such as individuals called chimaeras (Castella et al, 2009).…”

Curriculum and course materials for a forensic DNA biology course

“…The examinations were 20% multiple choice (20 questions) and 80% short answer/essay (7–10 questions). The research papers were based upon case studies in the primary literature selected from various journals including those shown in Table and approved by the instructor in advance. The students selected a wide range of topics as reflected in the table.…”