Identification of tetragametic human chimerism by routine DNA profiling.
Chimerism in humans is defined as the presence of two genetically different cell lines within the same organism. It is usually an acquired condition that is restricted to certain tissues and can be explained by therapeutic interventions such as blood transfusion or the transplantation of allogenic hematopoietic cells. Implications of such patients for forensic DNA testing have been described in the literature. In some rare cases, true inherited chimerism is observed. This so called tetragametic chimerism occurs via the fertilization of the two ova by two spermatozoa, followed by the fusion of early embryos and the development of an organism with intermingled cell lines. Such examples have been found in mice and other mammalian species including humans. We describe a phenotypically normal woman in whom tetragametic chimerism (46,XX/46,XX) was unexpectedly identified by STR typing during routine DNA profiling. Cytogenetic analysis proved to be a valuable tool for both independent confirmation and direct visualization of the two coexisting cell lines.
['Novotný|Jindřich|J|http://orcid.org/0000-0003-4214-2034', 'Lotz|Petra|P|', 'Müller|Stefan|S|', 'Steinlein|Ortrud|O|']
D000328:Adult D046528:Chimerism D016172:DNA Fingerprinting D004272:DNA, Mitochondrial D005260:Female D006650:Histocompatibility Testing D006801:Humans D017422:Sequence Analysis, DNA
DNA profiling Tetragametic chimerism Cytogenetic analysis STR analysis