Premium
Rapid prenatal diagnosis of common trisomies: discordant results between QF‐PCR analysis and karyotype analysis on long‐term culture for a case of trisomy 18 detected in CVS
Author(s) -
Allen S. K.,
Luharia A.,
Gould C. P.,
MacDonald F.,
Larkins S.,
Davison E. V.
Publication year - 2006
Publication title -
prenatal diagnosis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.956
H-Index - 97
eISSN - 1097-0223
pISSN - 0197-3851
DOI - 10.1002/pd.1582
Subject(s) - trisomy , karyotype , amniotic fluid , aneuploidy , chorionic villi , prenatal diagnosis , biology , chromosome analysis , down syndrome , products of conception , chromosome , chorionic villus sampling , genetics , andrology , fetus , pregnancy , medicine , gestation , gene
Objectives QF‐PCR analysis can be used as a rapid test to diagnose primary trisomy in prenatal samples. Mosaicism in CVS detected by QF‐PCR has previously been reported; however, no case has so far been reported in which the QF‐PCR result was completely discrepant to that of the karyotype analysis from a long‐term culture. Methods A CVS, referred because of a high serum screening risk of 1:10 for Down Syndrome and 1:110 for Edwards Syndrome, was tested by QF‐PCR analysis and chromosome analysis of cultured cells. Subsequent analyses were carried out on a follow‐up amniotic fluid sample and foetal tissue samples. Results Conflicting results were obtained between QF‐PCR analysis on two independent fronds from the chorionic villi and chromosome analysis on cultured CVS. Cytogenetic and molecular analysis on a subsequent amniotic fluid sample indicated trisomy 18 with no evidence of mosaicism. Analysis of follow‐up tissue confirmed trisomy in a foetal skin sample and mosaicism for trisomy 18 in four placental sites tested. Conclusion We report here an apparently normal CVS QF‐PCR result that was completely discrepant with the trisomy 18 positive karyotype result on long‐term culture. This has important implications regarding our current testing protocol. Copyright © 2006 John Wiley & Sons, Ltd.