High accuracy of quantitative fluorescence polymerase chain reaction combined with non‑invasive pre‑natal testing for mid‑pregnancy diagnosis of common fetal aneuploidies: A single‑center experience in China

Abstract

Quantitative fluorescence polymerase chain reaction (QF-PCR) may be used as a mid-pregnancy test to confirm the diagnosis of common fetal aneuploidies, but its use is controversial. The present study aimed to determine the value of QF-PCR for diagnostic confirmation of karyotyping and the impact of parental origin and meiosis stage on the detected aneuploidy. The present prospective cohort study included pregnant women (age, 21-45 years; gestational age, 17-25 weeks) who consulted between May 2015 and December 2016. Women were screened and only consecutive high-risk individuals were included (n=428). QF-PCR analysis of amniocytes was performed. Karyotype analysis was considered the gold standard. Parental karyotyping was performed if the embryo exhibited any aneuploidy. GeneMapper 3.2 was used for data analysis. There were no false-negative or false-positive QF-PCR results, with 100% concordance with the karyotype. The aneuploidy distribution (n=105) was 68.6% for trisomy 21, 19.0% for trisomy 18, 7.6% for sex chromosome aneuploidy, 3.8% for trisomy 13 and 1.0% for 48,XXX,+18. Regarding trisomy 21, most cases (86.1%) were of maternal origin, 8.3% paternal and 6.5% undefined. Trisomy 18 was 88.2% maternal and 11.8% paternal. Maternal meiosis stage errors in trisomy 21 mainly occurred in meiosis I, while the origin of trisomy 18 exhibited similar proportions between meiosis I and II. The combination of non-invasive pre-natal testing and QF-PCR may become a rapid and effective method for fetal aneuploidy detection. QF-PCR may provide more genetic information for clinical diagnosis and treatment than karyotyping alone.

Comprehensive phenotyping of fetuses with trisomy 18: a perinatal center experience

“…A study by Pan et al, 2016 reports 175 pregnancies with fetal nuchal translucency of more than 3.5 mm at 11–13 weeks of gestation and QF-PCR detected chromosomal anomalies in 30% of them including trisomy 18 in seven cases (4%) (Pan et al, 2016). Several studies support that QF-PCR can be used as a standalone procedure for targeted rapid aneuploidy diagnosis (Lildballe et al, 2014; Muthuswamy et al, 2015; Shin et al, 2016; Huo et al, 2019; Cottino et al, 2022). QF-PCR determined trisomy 18 in 6 (37%) fetuses in our perinatal cohort.…”

Prenatal diagnosis of syndromic alobar holoprosencephaly associated with digynic triploidy fetus

“…The accurate sonographic images were representative of alobar HPE [ 42 ]. Also, after the US scan, following a comprehensive consultation with a specialist in obstetrics and fetology expert, it was determined to complete supplementary genetic analysis, respectively amniocentesis and QF–PCR, as well as fetal karyotype [ 43 , 44 , 45 ]. QF–PCR is a rapid prenatal test that detects the presence of numerical aberrations of chromosomes 13, 18, 21, X, Y, which are the most common viable aneuploids, by amplification of repeated sequences at chromosome-specific polymorphic loci.…”

Genetics in prenatal diagnosis

“…[ 79 ] Occasionally, STR markers will be non-informative if both inherited alleles have the exact same number of repeats, but this is overcome by the use of multiple STR markers on a single chromosome. QF-PCR is a cost-effective method of aneuploidy screening,[ 80 ] has a very high detection rate for aneuploidies of chromosomes 13, 18, 21, X and Y of up to 98.6% to 100%[ 81 82 ] and a zero false-positive rate,[ 83 ] leading to its widespread clinical use in prenatal diagnosis of the common aneuploidies. However, QF-PCR does not provide information about structural variants, and follow-up with conventional cytogenetic analysis is still recommended to rule out inherited Robertsonian translocations, which has implications for subsequent pregnancies, particularly in the cases of trisomy 13 and 21.…”