Parentage of Hydatidiform Moles

Area of Science:

• Forensic Genetics
• Reproductive Biology

Background:

• Paternity testing typically involves analyzing short tandem repeat (STR) profiles from mother, child, and alleged father.
• Hydatidiform moles, abnormal products of conception, present unique challenges for genetic analysis due to their unusual genetic makeup.

Observation:

• Two paternity trios were analyzed, each involving a hydatidiform mole and a history of alleged sexual assault.
• One mole was dispermic (heterozygous), showing two paternal alleles at several loci, complicated by maternal decidual contamination.
• The second mole was diandric and diploid (homozygous), exhibiting only one paternal allele at all loci without maternal alleles.

Findings:

• Paternity indices (PIs) were calculated using traditional methods for single paternal alleles and adapted formulas for dispermic moles.
• Despite challenges like maternal contamination, STR analysis strongly supported the paternity of the alleged fathers in both cases.
• The classification of moles (dispermic vs. diandric/diploid) was crucial for accurate statistical reasoning.

Implications:

• This study demonstrates the utility of STR profiling in complex paternity cases involving hydatidiform moles.
• The findings highlight the importance of understanding mole pathogenesis for forensic genetic interpretation.
• Successful paternity determination in these challenging cases underscores the robustness of STR analysis in forensic science.