Genetic Evaluation of Spontaneous Miscarriages and Couples through Conventional and Modern Diagnostic Tools

Abstract

Background: Genetic causes of miscarriages have been extensively reported and studied in almost half of the first-trimester pregnancy losses, for that reason genetic investigations of the products of conceptions (POCs) are crucial to help identify possible genetic etiology. This information is helpful for the parents as it provides them with more acceptance of the loss and helps them recognize possible recurrence risks. Objective: This study aims to evaluate Quantitative Fluorescent-PCR (QF-PCR) for chromosomal aneuploidies detection in product of conception (POCs) as an alternate to conventional karyotyping and to explore potential parental chromosomal abnormalities causing recurrent spontaneous miscarriages. Methodology: A total of seventy-six products of conceptions (POCs) were obtained from the Gynecology department of Civil Hospital, Karachi. Further blood samples from forty-five couples were also collected in addition to ninety-three maternal blood samples. All of these samples were subjected to amplify short tandem repeat (STR) for common chromosomal aneuploidies (13, 18, and 21). Real-time QF-PCR was performed on 76 POCs on Sansure Biotech Inc, Changsha, China, using primers D13S631 and D13S634 for chromosome 13, D18S386 and D18S535 for chromosome 18, and D21S1411 and D21S1414 for chromosome 21. Parental blood samples were examined by both QF-PCR and karyotyping for cross-checking with their POC. Marker on Chromosome 16 was used as an internal control for the amplification of each reaction. Statistical analysis was done by using SPSS version 24. Results: QF-PCR analysis revealed chromosomal aneuploidies among twenty-nine POCs with the highest number of trisomy 13 followed by trisomy 21 and then trisomy 18 while all the parental samples were normal. Nine cases of chromosomal abnormalities were ruled out through karyotyping from parental blood samples further, a Robertsonian ttranslocation involving chromosome 21 was observed through conventional cytogenetics and interestingly the corresponding POC was found to have trisomy 21. Conclusion: This study’s findings endorsed QF-PCR as an efficient technique to detect chromosomal aneuploidies. Advantages of QF-PCR over conventional karyotyping is that it is less laborious, has lesser turnaround time, is more economical, and has a low failure rate.

Keywords

• miscarriage
• chromosomal aneuploidies
• chromosomal abnormalities
• numerical aberration
• short tandem repeat.