Trisomy 20 mosaicism – a subtle phenotype


  • Inês Medeiros Department of Pediatrics, Hospital de Braga
  • Catarina Faria Department of Pediatrics, Hospital de Braga
  • Fábia Carvalho Department of Pediatrics, Hospital de Braga
  • Miguel Gonçalves Rocha Department of Genetics, Hospital de Braga
  • Helena Silva Department of Pediatrics, Hospital de Braga



Mosaicism, phenotype, trisomy 20


Introduction: Trisomy 20 mosaicism is one of the most common cytogenetic abnormalities found in prenatal diagnosis. The outcome of these pregnancies is normal in most of the reported cases, but clinical implications of diagnosis and prognosis in a long term basis are not clear.
Case report: The authors present a case of trisomy 20 mosaicism, with no prenatal diagnosis, followed-up for a period of 13 years, aiming to demonstrate the existence of a subtle phenotype, which represents a challenge in diagnosis.
Discussion/Conclusion: No specific phenotype has been associated with the cytogenetic findings but certain features, although subtle, appear to be consistent.


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How to Cite

Medeiros I, Faria C, Carvalho F, Rocha MG, Silva H. Trisomy 20 mosaicism – a subtle phenotype. REVNEC [Internet]. 2018Oct.17 [cited 2024May28];27(3):182-4. Available from:



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