Iris Schrijver

Publication Details

  • Rare Sequence Variation in the Genome Flanking a Short Tandem Repeat Locus Can Lead to a Question of "Nonmaternity" JOURNAL OF MOLECULAR DIAGNOSTICS Deucher, A., Chiang, T., Schrijver, I. 2010; 12 (3): 384-389


    Typing of STR (short tandem repeat) alleles is used in a variety of applications in clinical molecular pathology, including evaluations for maternal cell contamination. Using a commercially available STR typing assay for maternal cell contamination performed in conjunction with prenatal diagnostic testing, we were posed with apparent nonmaternity when the two fetal samples did not demonstrate the expected maternal allele at one locus. By designing primers external to the region amplified by the primers from the commercial assay and by performing direct sequencing of the resulting amplicon, we were able to determine that a guanine to adenine sequence variation led to primer mismatch and allele dropout. This explained the apparent null allele shared between the maternal and fetal samples. Therefore, although rare, allele dropout must be considered whenever unexplained homozygosity at an STR locus is observed.

    View details for DOI 10.2353/jmoldx.2010.090201

    View details for Web of Science ID 000277531700018

    View details for PubMedID 20203001

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