FAQs
Familial Variant Testing
What if discordant relatedness is detected in samples sent for Familial Variant Testing (FVT)?
In our Quality Control (QC) process, a relatedness algorithm is run as part of our pipeline for familial variant tests when Blueprint Genetics previously tested a family member AND this family member was linked to the current order. This is performed to ensure the sequenced samples belong to individuals who are blood relatives. This process estimates the degree of relatedness (first degree, second degree, etc) and is not a formal assessment of maternity/paternity.
Discordant relatedness occurs when the estimated degree of relatedness between 2 individuals is inconsistent with the reported relationship, and has been eliminated out an internal sample mix-up to the best of our ability. Discordant relatedness could be identified for several reasons including but not limited to sample mix-up, undisclosed bone marrow or stem cell transplant, and misattributed parentage.
If the ability to interpret and classify the requested variant(s) is impacted by the identification of discordant relatedness, the ordering provider will be contacted to discuss the next steps, including the option of submitting a new sample for the individual implicated. If we continue to identify discordant relatedness on the new sample, we will automatically proceed with reporting the genotype as identified in the new sample. Information about discordant relatedness will not be included on the patient report. In addition, this individual’s data will be excluded from any segregation analysis within the family.
If discordant relatedness is identified and there is no impact on the ability to interpret and classify the requested variant(s), the ordering provider will not be informed of the discrepancy, and we will report the genotype identified in the sample. Information about discordant relatedness will not be included on the patient report. In addition, this individual’s data will be excluded from any segregation analysis within the family, and there will be no follow-up reports issued for the index patient indicating whether the requested variant(s) were inherited or not.