Abstract
We present a family with multiple carriers of a subtle balanced translocation t(14;21)(q21.2;q21.2) and three patients with a resultant adjacent-2 malsegregation containing a +der(14)t(14;21)(q21.2;q21.2),-21 in their chromosome complement. The initial study was performed when a 2-month-old female was referred to genetics clinic for evaluation of developmental delay, growth retardation, and failure to thrive. Physical findings included prominent eyes, micrognathia, prominent and simple external ears, camptodactyly, contractures of the wrists, ankles, and hips, hypoplasia of the corpus callosum, prominent atria and occipital horns, cerebellopontine hypoplasia; and small atrial septal defect. High resolution chromosomes showed an extra band on the proximal 21q and fluorescence in situ hybridization (FISH) demonstrated only one signal for the centromere of 21. Karyotypes of the parents and grandparents revealed that the mother and maternal grandfather were carriers of a balanced translocation, and the propositus contained an unbalanced chromosome complement with partial duplication of proximal 14q and partial deletion of proximal 21q. Investigations performed on an institutionalized maternal aunt revealed identical karyotypic abnormalities as in the propositus. More recently, array comparative genomic hybridization (aCGH) on a subsequent child with multiple congenital anomalies further out in the extended family allowed for more accurate identification of the breakpoints. Our investigation includes analysis on a total of 11 family members spanning three generations. Among those investigated, there were no living members with other possible consequential unbalanced translocations or with adjacent-2 segregation resulting in -14,+der(21). Chromosome rearrangements require FISH and aCGH studies for accurate identification and elucidation of the abnormality and breakpoints.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: 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.