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Fragile X syndrome in a girl with variant Turner syndrome and an isodicentric X chromosome
  1. Nattaporn Tassanakijpanich1,2,
  2. Rachel Wright3,
  3. Flora Tassone2,4,
  4. Suma P Shankar2,5 and
  5. Randi Hagerman2,5
  1. 1Pediatrics, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla, Thailand
  2. 2UC Davis MIND Institute, UC Davis Health, Sacramento, California, USA
  3. 3Biology, Texas A&M University, College Station, Texas, USA
  4. 4Biochemistry and Molecular Medicine, UC Davis, School of Medicine, Davis, California, USA
  5. 5Pediatrics, UC Davis, School of Medicine, Sacramento, California, USA
  1. Correspondence to Dr Randi Hagerman; rjhagerman{at}


Fragile X (FXS) and Turner (TS) syndromes are X-chromosome-associated disorders. Herein, we report the case of a girl in middle childhood with bicuspid aortic valve in infancy, growth failure, global developmental delay (GDD), visual problems, and coexisting attention-deficit/hyperactivity and anxiety disorders. A high-resolution karyotype in 20 cells revealed 46,X,Idic(X)(p11.21)[19]/45,X[1], suggestive of variant TS. Given her atypical phenotype, subsequent DNA testing was performed. Four FMR1 cytosine-guanine-guanine repeats (30, 410, 580 and 800) were identified, confirming the additional FXS diagnosis. This case study highlights the importance of additional genetic testing in individuals with atypical variant TS, such as unexplained GDD and distinct facial characteristics. The additional FXS diagnosis prompted new therapeutic development for the patient to advance precision healthcare.

  • Paediatrics (drugs and medicines)
  • Genetics
  • Developmental paediatrocs

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  • Contributors NT and RH drafted the manuscript. NT, RH, RW, FT and SS made substantial contributions to the conception of the work, data acquisition, data interpretation, critical revisions and approval of the submitted version of the manuscript.

  • Funding This study was funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development (HD036071); the Azrieli Foundation; the National Center for Advancing Translational Sciences and National Institutes of Health (UL1 TR001860); and the MIND Institute Intellectual and Developmental Disabilities Research Center (U54 HD079125).

  • Case reports provide a valuable learning resource for the scientific community and can indicate areas of interest for future research. They should not be used in isolation to guide treatment choices or public health policy.

  • Competing interests RH is funded by the Azrieli Foundation for a controlled trial of metformin in FXS. FT received funding from the Azrieli Foundation and from Zynerba for studies in FXS. SS holds the Children’s Miracle Network endowed chair in paediatrics and receives grant support from it. The other authors declare that they have no competing interests.

  • Provenance and peer review Not commissioned; externally peer reviewed.