Document Detail

Three different origins for apparent triploid/diploid mosaics.
MedLine Citation:
PMID:  12868076     Owner:  NLM     Status:  MEDLINE    
Four apparent triploid/diploid mosaic cases were studied. Three of the cases were detected at prenatal diagnosis and the other was of an intellectually handicapped, dysmorphic boy. Karyotypes were performed in multiple tissues if possible, and the inheritance of microsatellites was studied with DNA from fetal tissues and parental blood. Non-mosaic triploids have a different origin from these mosaics with simple digyny or diandry documented in many cases. Three different mechanisms of origin for these apparent mosaics were detected: (1) chimaerism with karyotypes from two separate zygotes developing into a single individual, (2) delayed digyny, by incorporation of a pronucleus from a second polar body into one embryonic blastomere, and (3) delayed dispermy, similarly, by incorporation of a second sperm pronucleus into one embryonic blastomere. In three of the four cases, there was segregation within the embryos of triploid and diploid cell lines into different tissues from which DNA could be isolated. In case 2 originating by digyny, the same sperm allele at each locus could be detected in both triploid and diploid tissues, which is supportive evidence for the involvement of a single sperm and for true mosaicism rather than chimaerism. Similarly, in case 4 originating by dispermy, the same single ovum allele at each locus could be detected in diploid and triploid tissues, confirming mosaicism. In the chimaeric case (case 3), the diploid line had the karyotype 47,XY,+16 while the triploid line was 69,XXY. This suggests a chimaera, since, in a true mosaic, the triploid line should also contain the additional chromosome 16. Supporting the interpretation of a chimaeric origin for this case, the DNA data showed that the triploidy was consistent with MII non-disjunction (i.e. involving a diploid ovum). In the mosaic cases (1, 2, 4), there was no evidence of the involvement of a diploid sperm or a diploid ova, and in triploid/diploid mosaicism, an origin from a diploid gamete is excluded, since all such conceptuses would be simple triploids. In one of these triploid/diploid mosaics detected at prenatal diagnosis by CVS, the triploid line seemed to be sequestered into the extra-fetal tissues (confined placental mosaicism). This fetus developed normally and a normal infant was born with no evidence of triploidy in newborn blood or cord blood at three months of age.
Art Daniel; Zhanhe Wu; Artur Darmanian; Felicity Collins; Julianne Jackson
Related Documents :
8843616 - Prenatal diagnosis of persistent right umbilical vein.
20814946 - Tissue-limited mosaicism for monosomy 13.
2486026 - Clinical follow-up of prenatally diagnosed isolated ventriculomegaly, microcephaly and ...
24525686 - Pharmacology of attention and arousal in the low level patient.
1926836 - Adenocarcinoma of the small intestine in crohn's disease: a unique finding.
2327446 - Postpartum cardiovascular complications after bromocriptine and cocaine use.
Publication Detail:
Type:  Case Reports; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Prenatal diagnosis     Volume:  23     ISSN:  0197-3851     ISO Abbreviation:  Prenat. Diagn.     Publication Date:  2003 Jul 
Date Detail:
Created Date:  2003-07-17     Completed Date:  2003-12-04     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  8106540     Medline TA:  Prenat Diagn     Country:  England    
Other Details:
Languages:  eng     Pagination:  529-34     Citation Subset:  IM    
Copyright Information:
Copyright 2003 John Wiley & Sons, Ltd.
Departments of Cytogenetics, Western Sydney Genetics Program, The Children's Hospital at Westmead, P/O Box 3515, Parramatta, NSW 2124, Australia.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Infant, Newborn
Microsatellite Repeats
Mosaicism / diagnosis*,  genetics*
Polymerase Chain Reaction
Prenatal Diagnosis*

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Immersion fixation with Carnoy solution for conventional immunohistochemical detection of particular...
Next Document:  Health professionals' reports of information given to parents following the prenatal diagnosis of se...