These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Application of real-time PCR of sex-independent insertion-deletion polymorphisms to determine fetal sex using cell-free fetal DNA from maternal plasma.
    Author: Ho SS, Barrett A, Thadani H, Asibal CL, Koay ES, Choolani M.
    Journal: Clin Chem Lab Med; 2015 Jul; 53(8):1189-95. PubMed ID: 25581758.
    Abstract:
    BACKGROUND: Prenatal diagnosis of sex-linked disorders requires invasive procedures, carrying a risk of miscarriage of up to 1%. Cell-free fetal DNA (cffDNA) present in cell-free DNA (cfDNA) from maternal plasma offers a non-invasive source of fetal genetic material for analysis. Detection of Y-chromosome sequences in cfDNA indicates presence of a male fetus; in the absence of a Y-chromosome signal a female fetus is inferred. We aimed to validate the clinical utility of insertion-deletion polymorphisms (INDELs) to confirm presence of a female fetus using cffDNA. METHODS: Quantitative real-time PCR (qPCR) for the Y-chromosome-specific sequence, SRY, was performed on cfDNA from 82 samples at 6-39 gestational weeks. In samples without detectable SRY, qPCRs for eight INDELs were performed on maternal genomic DNA and cfDNA. Detection of paternally inherited fetal alleles in cfDNA negative for SRY confirmed a female fetus. RESULTS: Fetal sex was correctly determined in 77/82 (93.9%) cfDNA samples. SRY was detected in all 39 samples from male-bearing pregnancies, and none of the 43 female-bearing pregnancies (sensitivity and specificity of SRY qPCR is therefore 100%; 95% CI 91%-100%). Paternally inherited fetal alleles were detected in 38/43 samples with no SRY signal, confirming the presence of a female fetus (INDEL assay sensitivity is therefore 88.4%; 95% CI 74.1%-95.6%). Since paternally inherited fetal INDELs were not used in women bearing male fetuses, the specificity of INDELs cannot be calculated. Five cfDNA samples were negative for both SRY and INDELS. CONCLUSIONS: We have validated a non-invasive prenatal test to confirm fetal sex as early as 6 gestational weeks using cffDNA from maternal plasma.
    [Abstract] [Full Text] [Related] [New Search]