Down Syndrome Resulting from a Rare non-Robertsonian Translocation t(11;21)(p13;q22)

• Main Authors: Dante Bruno Avanso Rosan (Author), Priscila L. Dourado (Author), Andréa Engracia Ruiz (Author), Valéria C.C. Ferrarezi da Silva (Author), Cristina Benitez Vendrame (Author), Andréa B. Carvalho-Salles (Author), Brasilina de F. Mafei (Author), Agnes Cristina Fett -Conte (Author)
• Format: Book
• Published: Faculdade de Medicina de São José do Rio Preto, 2021-08-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.

Summary

Introduction: Down syndrome (DS) is a common genetic disorder, occurring in approximately 1 in 700 births. It results from an extra copy (triplication) of the whole or part of the long arm of chromosome 21 caused by different cytogenetic alterations: free trisomy, Robertsonian translocations, mosaicism, duplication of the critical region and other structural rearrangements. Non-Robertsonian chromosome translocations are very rare events with few cases reported. Case Report: We identified the non-Robertsonian translocation t(11;21)(p13;q22) and two chromosomes 21 in a female child referred with a clinical diagnosis of trisomy 21.  The infant developed the transient myeloproliferative disorder at 17 months. Cytogenetic analysis was performed in lymphocytes and bone marrow metaphases according to standard procedure - G banding and fluorescence in situ hybridization.  The karyotype study of the parents revealed that her phenotypically normal mother carries the same reciprocal translocation. Conclusion: This is the second report of the translocation t(11;21)(p13;q22),  the first one resulting in DS.  This description expands knowledge about cytogenetic variability in the etiology of DS. Future studies are needed to investigate the long-term clinical effects of the trisomy 21 associated with t(11;21)(p13;q22).

Item Description

10.17696/2318-3691.28.1.2021.1795
2318-3691