de Pater JM, Kroes HY, Verschuren M, van Oppen ACC, Albrechts JCM, Engelen JJM. Mosaic trisomy (8)(p22 --> pter) in a fetus caused by a supernumerary marker chromosome without alphoid sequences.
Prenat Diagn 2005;
25:151-5. [PMID:
15712342 DOI:
10.1002/pd.1097]
[Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE
Our objective was to characterise a marker chromosome in cultured amniocytes of a fetus with a mos 47,XX,+mar[3]/46,XX[14] karyotype.
METHODS
The indication for prenatal cytogenetic analysis of cultured amniocytes was advanced maternal age. Classic banding techniques (GTG- and C-banding) were performed. Microdissection combined with reverse painting was used to disclose the exact origin of the marker; the result was confirmed by chromosome painting and FISH with band-specific probes.
RESULTS
Analysis of GTG-banded chromosomes showed a small marker chromosome in 3 of the 17 colonies analysed. Subsequently, C-banding showed no alphoid sequences, suggesting the presence of a neocentromere. The parent's karyotypes were normal. After normal ultrasound findings, the parents decided to continue the pregnancy. Chromosome analysis in peripheral blood after birth demonstrated that the marker chromosome was present in 50% of the lymphocytes. Using microFISH, the marker was further characterised and appeared to be derived from chromosome region (8)(p22 --> pter).
CONCLUSION
Accurate identification of the marker chromosome was very important for prenatal counselling. Combining the results of GTG- and C-banding analysis with the results of the (micro)FISH, we concluded that the patient's karyotype is: mos 47,XX,+mar.rev ish der(8)(p22 --> pter)[50]/46,XX[50].
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