A child with complementary mosaic trisomy 8 and mosaic trisomy 21; clinical description of Warkany-Down syndrome and mechanism of origin

Magda McGregor-Schuerman, Audrey Lo Fo Sang, Santusha Bihari, Natasja Ramdajal, Ron F Suijkerbuijk, Conny Ma van Ravenswaaij-Arts*

*Corresponding author for this work

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Aneuploidy mosaicism involving two complementary different autosomal trisomy cell lines is extremely rare. Although a mosaic double trisomy 8/trisomy 21 has been described in literature, this is the first report of Warkany (+8)-Down (+21) syndrome due to two complementary mosaic trisomy cell lines. The phenotype of the male patient with Warkany-Down syndrome includes upslanting palpebral fissures, hypertelorism, small low-set ears with unilateral aural stenosis, large and broad hands and feet with deep palmar and plantar creases, bilateral cryptorchidism, generalized mild hypotonia and transient neonatal thrombocytopenia. At the age of two years, his developmental quotient is around 50. His height, weight and head circumference are below the third centile. We speculate on the mechanism of origin of the complementary trisomy cell lines based on molecular cytogenetic studies that showed no evidence for a chimera.

Original languageEnglish
Article number103922
Number of pages5
JournalEuropean journal of medical genetics
Issue number6
Early online date30-Mar-2020
Publication statusPublished - Jun-2020


  • Warkany syndrome
  • Down syndrome
  • Mosaic trisomy 8
  • Mosaic trisomy 21
  • Double autosomal trisomy
  • Double aneuploidy
  • Nondisjunction

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