title: Frontal Aslant Tract Abnormality on Diffusion Tensor Imaging in an Aphasic Patient With 49, XXXXY Syndrome.
abstract: BACKGROUND
  The karyotype 49, XXXXY is one of the most severe forms of chromosome aneuploidy and is characterized clinically by developmental delay and profound language impairment, particularly involving expressive language functions. We describe the neurocognitive profile and structural anatomy of language pathway in a 2-year-old boy with 49, XXXXY syndrome with expressive aphasia.
  
  
  METHODS
  Retrospective chart review of the patient was performed. We characterized the language deficits using neuropsychologic testing. We further studied the language pathways using diffusion tensor imaging analytical technique.
  
  
  RESULTS
  The neurocognitive profile of the patient showed relative weakness of expressive language skills compared with other domains. Diffusion tensor imaging analysis demonstrated a poorly developed frontal aslant tract, a weak indirect segment of arcuate fasciculus, and normally developed direct segment of arcuate fasciculus. The frontal aslant tract is a novel pathway that connects the Broca's area with the anterior cingulate and presupplementary motor area and plays a role in the "motor stream" of language.
  
  
  CONCLUSIONS
  A poorly developed frontal aslant tract may underlie the expressive language deficits and provide some insight into the role of X chromosome in modulating the development of language tracts.
authors.affiliation: Department of Neurology, Wayne State University School of Medicine, Detroit, Michigan. Electronic address: monicadhakar@gmail.com.
authors.forename: Monica B
authors.initials: MB
authors.lastname: Dhakar
authors.affiliation: Department of Pediatrics and Neurology, Wayne State University School of Medicine, Children's Hospital of Michigan, Detroit, Michigan.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Ilyas
authors.affiliation: Department of Pediatrics and Neurology, Wayne State University School of Medicine, Children's Hospital of Michigan, Detroit, Michigan.
authors.forename: Jeong-Won
authors.initials: JW
authors.lastname: Jeong
authors.affiliation: Department of Pediatrics and Neurology, Wayne State University School of Medicine, Children's Hospital of Michigan, Detroit, Michigan.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Behen
authors.affiliation: Department of Pediatrics and Neurology, Wayne State University School of Medicine, Children's Hospital of Michigan, Detroit, Michigan. Electronic address: Harry.Chugani@nemours.org.
authors.forename: Harry T
authors.initials: HT
authors.lastname: Chugani
mesh_terms: D000782:Aneuploidy; D001039:Aphasia, Broca / Q000473:pathology*; D002675:Child, Preschool; D056324:Diffusion Tensor Imaging; D006801:Humans; D008297:Male; D009434:Neural Pathways / Q000473:pathology; D025064:Sex Chromosome Disorders / Q000473:pathology*; D013577:Syndrome; D066127:White Matter / Q000473:pathology*
keywords: 49, XXXXY; arcuate fasciculus; chromosome aneuploidy; language