MISDIAGNOSIS OF HOMOZYGOUS ALPHA-THALASSAEMIA 1 MAY OCCUR IF POLYMERASE CHAIN REACTION ALONE IS USED IN PRENATAL DIAGNOSIS
The polymerase chain reaction (PCR) is a quite sensitive diagnostic tool but its specificity may be hampered because of contamination of foreign DNA. In order to determine the diagnostic accuracy of PCR in diseases due to gross gene deletion, a total of 180 fetuses at risk of homozygous South‐East A...
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Published in | Prenatal diagnosis Vol. 17; no. 6; pp. 505 - 509 |
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Main Authors | , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Chichester, UK
John Wiley & Sons, Ltd
01.06.1997
Wiley |
Subjects | |
Online Access | Get full text |
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Summary: | The polymerase chain reaction (PCR) is a quite sensitive diagnostic tool but its specificity may be hampered because of contamination of foreign DNA. In order to determine the diagnostic accuracy of PCR in diseases due to gross gene deletion, a total of 180 fetuses at risk of homozygous South‐East Asian deletion (SEA) of alpha‐globin genes were included for study. Both PCR and Southern hybridization (SH) were performed. By PCR, three of 43 affected fetuses were misdiagnosed as heterozygotes; four of 50 normal fetuses were misdiagnosed as heterozygotes; and four of 87 heterozygotes were misdiagnosed, two as normal and two as affected. Misdiagnosis in affected and normal fetuses was most likely due to maternal DNA contamination, while misdiagnosis in heterozygotes was probably due to a failed PCR. In the experiments with PCR in which we added DNA from a carrier woman to an affected or a normal fetus, a level of 1/64 and 1/16 contamination resulted in the appearance of normal and SEA breakpoint sequences, respectively. In the SH experiments using artificially contaminated DNA, a level of 1/4 contamination showed the normal and SEA bands, respectively, while a contamination level lower than 1/8 and 1/16 respectively did not reveal contamination bands. The high sensitivity of PCR makes it easier to amplify contaminated DNA. For accurate prenatal diagnosis, PCR should be performed very carefully and SH seems to be a useful back‐up. © 1997 John Wiley & Sons, Ltd. |
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Bibliography: | ark:/67375/WNG-6FG3ZM40-F National Science Council of the Republic of China on Taiwan - No. NSC 81-0412-B002-32; No. NSC 83-0412-B002-332 ArticleID:PD104 istex:381B9A78CB57843A1ECE5F7B2437A32FFE192C78 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0197-3851 1097-0223 |
DOI: | 10.1002/(SICI)1097-0223(199706)17:6<505::AID-PD104>3.0.CO;2-R |