Inversion-duplication of bands q13→q21 of human chromosome 9 |
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Authors: | Sunny Luke Ram S. Verma Rhandy Pebenito Michael J. Macera |
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Affiliation: | Long Island College Hospital, Brooklyn, New York |
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Abstract: | Structural abnormalities involving heterochromatic regions of the human genome are difficult to characterize because these segments are G-band negative by GTG technique, a routinely used procedure in clinical cytogenetic laboratories. Chromosome abnormalities of such cases have gone undetected or were incorrectly characterized because these regions are so-called heteromorphisms or variants. Consequently, much anxiety has been aroused by the confusion between a chromosome abnormality and a normal heteromorphic variant. We report the first documented case with a so-called highly unusual h region of chromosome 9 which is not a variation but a structural rearrangement involving a paracentric inversion and a duplication. The major clinical features were psychomotor retardation, microcephaly, narrow palpebral fissures, renal and genital anomalies, vertebral anomalies, protruding tongue, and learning and behavioral problems. A concise review of variable duplicated segments of 9q is also provided. |
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Keywords: | 9q syndrome inversion duplication heteromorphism secondary constriction region |
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