QF-PCR as a stand-alone test for prenatal samples: the first 2 years' experience in the London region.
OBJECTIVE
To analyse the results of the first 2 years of a QF-PCR stand-alone testing strategy for the prenatal diagnosis of aneuploidy in the London region and to determine the advantages and disadvantages of this policy.


METHODS
A review of the results of 9737 prenatal samples received for exclusion of chromosome abnormalities. All samples were subjected to QF-PCR testing for common aneuploidies but only samples fulfilling specific criteria subsequently had a full karyotype analysis.


RESULTS
Of the 9737 samples received, 10.3% had a chromosome abnormality detected by QF-PCR testing. Of the 7284 samples received with no indication for karyotype analysis, 25 (0.3%) received a normal QF-PCR result but subsequently had an abnormal karyotype detected either prenatally as a privately funded test or postnatally. Of these samples, without subsequent abnormal ultrasound findings, five had a chromosome abnormality associated with a poor prognosis, representing 0.069% of samples referred for Down syndrome testing.


CONCLUSIONS
While back-up karyotyping is required for some samples, using QF-PCR as a stand-alone prenatal test for pregnancies without ultrasound abnormalities reduces costs, provides rapid delivery of results, and avoids ambiguous and uncertain karyotype results, reducing parental anxiety.
Hills
Alison
A
Cytogenetics Department, GSTS Pathology, Guy's and St Thomas' NHS Foundation Trust, London, UK. alison.hills@gsts.com
Donaghue
Celia
C
Waters
Jonathan
J
Waters
Katie
K
Sullivan
Caroline
C
Kulkarni
Abhijit
A
Docherty
Zoe
Z
Mann
Kathy
K
Ogilvie
Caroline Mackie
CM
D000465:Algorithms; D000782:Aneuploidy; D001800:Blood Specimen Collection / Q000592:standards; D025063:Chromosome Disorders / Q000175:diagnosis* / Q000453:epidemiology / Q000235:genetics; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D007621:Karyotyping / Q000379:methods; D008131:London / Q000453:epidemiology; D016133:Polymerase Chain Reaction / Q000379:methods* / Q000592:standards / Q000706:statistics & numerical data; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods* / Q000706:statistics & numerical data; D012107:Research Design; D012189:Retrospective Studies