Abstract
BackgroundTriplication is a rare chromosomal anomaly. We identified a de novo triplication of 11q12.3 in a patient with developmental delay, distinctive facial features, and others. In the present study, we discuss the mechanism of triplications that are not embedded within duplications and potential genes which may contribute to the phenotype.ResultsThe identified triplication of 11q12.3 was 557 kb long and not embedded within the duplicated regions. The aberrant region was overlapped with the segment reported to be duplicated in 2 other patients. The common phenotypic features in the present patient and the previously reported patient were brain developmental delay, finger abnormalities (including arachnodactuly, camptodactyly, brachydactyly, clinodactyly, and broad thumbs), and preauricular pits.ConclusionsTriplications that are not embedded within duplicated regions are rare and sometimes observed as the consequence of non-allelic homologous recombination. The de novo triplication identified in the present study is novel and not embedded within the duplicated region. In the 11q12.3 region, many copy number variations were observed in the database. This may be the trigger of this rare triplication. Because the shortest region of overlap contained 2 candidate genes, STX5 and CHRM1, which show some relevance to neuronal functions, we believe that the genomic copy number gains of these genes may be responsible for the neurological features seen in these patients.
Highlights
We identified a de novo triplication that was not embedded within a duplication, in a patient with developmental delay and distinctive features
By use a 60K array, a gain of the genomic copy number was identified on the 11q12.3 region with a mean log2 ratio of 1.132548, indicating a triplicated segment of 557 kb with a description of arr
Compared to the location of the triplication that resulted from DUP-TRP/INV-DUP, the triplicated region identified in the present study was not embedded within the duplicated segments and there was no duplicated region around the triplicated segment (Figure 2)
Summary
We identified a de novo triplication of 11q12.3 in a patient with developmental delay, distinctive facial features, and others. We discuss the mechanism of triplications that are not embedded within duplications and potential genes which may contribute to the phenotype. Many chromosomal triplications that are visible by conventional karyotyping have been reported. Such chromosomal rearrangements are considered to be caused by abnormal meiotic chromosomal recombinations [1,2]. The introduction of chromosomal microarray testing allowed the identification of invisible small triplications. We have performed chromosomal microarray testing of >1,000 samples in our institution, only 3 invisible triplications have been identified to date (Figure 1).
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
