DNA analysis in disputed parentage: the occurrence of two apparently false exclusions of paternity, both at short tandem repeat (STR) loci, in the one child.

In cases of disputed paternity investigated by DNA analysis, it is generally accepted that at least two independent exclusions be observed before concluding that a putative father is not the biological father of the child. We report here a case in which two apparent exclusions of paternity were obtained (at the loci FESFPS and TPOX), from a total of nineteen loci examined (short tandem repeats, AMFLPs, DQA1, Polymarkers). The combined paternity index of the other seventeen loci, and of two multilocus probes (33.15 and 33.6) would exceed twenty-eight trillion to one. In the absence of any alternative putative father (including close relatives of the man tested), we concluded that the most likely explanation for these results was that the putative father was indeed the biological father, but that two independent mutations had occurred in either the ovum and/or spermatozoon. We have altered our internal laboratory criterion for exclusion of paternity to require exclusions in three independent loci.

Rotavirus neutralizing protein VP7: antigenic determinants investigated by sequence analysis and peptide synthesis.

The rotavirus neutralizing antigen, VP7, is a 37,000-molecular-weight glycoprotein which is a major component of the outer shell of the virion. The amino acid sequence of VP7 for strain S2 (human serotype 2) and Nebraska calf diarrhea virus (bovine serotype) has been inferred from the nucleic acid sequence of cloned copies of genomic segment nine. Comparison of the amino acid sequences of these two VP7 proteins with those already determined for other rotavirus strains reveals extensive sequence conservation between serotypes with clusters of amino acid differences sited predominantly in hydrophilic domains of the protein. Six peptides have been synthesized that span the hydrophilic regions of the molecule. Antisera to these peptides both recognize the respective homologous peptides in a solid-phase radioimmunoassay and bind to denatured VP7 in a Western blot. However, none of the antisera either recognize virus or exhibit significant neutralizing activity, indicating that these peptide sequences are not available on the surface of the virus.