title: Aberrant frontal lobe maturation in adolescents with fragile X syndrome is related to delayed cognitive maturation.
abstract: BACKGROUND
  Fragile X syndrome (FXS) is the most common known heritable cause of intellectual disability. Prior studies in FXS have observed a plateau in cognitive and adaptive behavioral development in early adolescence, suggesting that brain development in FXS may diverge from typical development during this period.
  
  
  METHODS
  In this study, we examined adolescent brain development using structural magnetic resonance imaging data acquired from 59 individuals with FXS and 83 typically developing control subjects aged 9 to 22, a subset of whom were followed up longitudinally (1-5 years; typically developing: 17, FXS: 19). Regional volumes were modeled to obtain estimates of age-related change.
  
  
  RESULTS
  We found that while structures such as the caudate showed consistent volume differences from control subjects across adolescence, prefrontal cortex (PFC) gyri showed significantly aberrant maturation. Furthermore, we found that PFC-related measures of cognitive functioning followed a similarly aberrant developmental trajectory in FXS.
  
  
  CONCLUSIONS
  Our findings suggest that aberrant maturation of the PFC during adolescence may contribute to persistent or increasing intellectual deficits in FXS.
authors.affiliation: Department of Psychiatry, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Signe
authors.initials: S
authors.lastname: Bray
authors.forename: Melissa
authors.initials: M
authors.lastname: Hirt
authors.forename: Booil
authors.initials: B
authors.lastname: Jo
authors.forename: Scott S
authors.initials: SS
authors.lastname: Hall
authors.forename: Amy A
authors.initials: AA
authors.lastname: Lightbody
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Walter
authors.forename: Kelly
authors.initials: K
authors.lastname: Chen
authors.forename: Swetapadma
authors.initials: S
authors.lastname: Patnaik
authors.forename: Allan L
authors.initials: AL
authors.lastname: Reiss
mesh_terms: D000293:Adolescent; D000375:Aging / Q000502:physiology; D002648:Child; D003071:Cognition / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D005600:Fragile X Syndrome / Q000473:pathology* / Q000523:psychology*; D005625:Frontal Lobe / Q000254:growth & development* / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009483:Neuropsychological Tests; D017397:Prefrontal Cortex / Q000254:growth & development / Q000473:pathology; D055815:Young Adult