title: Differences in neuropsychological and behavioral parameters and brain structure in patients with familial adenomatous polyposis: a sibling-paired study.
abstract: BACKGROUND
  Familial adenomatous polyposis (FAP) is an autosomal dominant hereditary colon cancer syndrome caused by mutations in adenomatous polyposis coli (APC) with both colonic and extra-colonic manifestations. Case reports have noted an association with FAP and intellectual disability and animal studies have shown that APC is implicated in neural development and function, but no studies have investigated neuropsychological, behavioral, or structural brain characteristics of patients with FAP.
  
  
  METHODS
  We undertook a pilot, sibling-pair study comparing three patients with FAP to their sex-matched siblings without FAP. Each sibling pair underwent neuropsychological testing by a blinded examiner, high resolution brain MRI scans, and the mother of each pair rated her children's adaptive life skills and behavioral and emotional characteristics. Given the small number of study participants in this pilot study, quantitative comparisons of results were made by subtracting the score of the non-FAP sibling from the FAP patient on the various neuropsychological tests and parent rating questionnaires to calculate a difference, which was then divided by the standard deviation for each individual test to determine the difference, corrected for the standard deviation. Diffusion numbers in multiple regions of the brain as assessed by MRI were calculated for each study participant.
  
  
  RESULTS
  We found similarity between siblings in all three pairs on a wide range of neuropsychological measures (general intelligence, executive function, and basic academic skills) as tested by the psychologist as well as in descriptions of adaptive life skills as rated by mothers. However, mothers' ratings of behavioral and emotional characteristics of two of the three pairs showed differences between the siblings, specifically that the patients with FAP were found to have more behavioral and emotional problems compared to their siblings. No differences in brain structure were identified by MRI.
  
  
  CONCLUSIONS
  We report the first study exploring neuropsychological, behavioral, emotional, and structural brain characteristics of patients with FAP and found subjective differences as assessed by maternal perception in behavioral and emotional characteristics in patients with FAP compared to their siblings. Larger studies are needed to elucidate the relationship, if any, between FAP and brain function.
authors: Cruces University Hospital, Medical Faculty, Basque Country University, Biscay, Spain.
authors: Ana Sánchez
authors: AS
authors: Azofra
authors: Division of Gastroenterology, University of California, San Francisco, 1701 Divisadero, San Francisco, CA 94115 USA.
authors: Trilokesh D
authors: TD
authors: Kidambi
authors: Pediatric Clinical Research Centery, Clinical and Translational Science Institute, University of California, San Francisco, San Francisco, CA USA.
authors: Rita J
authors: RJ
authors: Jeremy
authors: Hereditary GI Cancer Prevention Program, Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA USA.
authors: Peggy
authors: P
authors: Conrad
authors: Hereditary GI Cancer Prevention Program, Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA USA.
authors: Amie
authors: A
authors: Blanco
authors: Hereditary GI Cancer Prevention Program, Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA USA.
authors: Megan
authors: M
authors: Myers
authors: Division of Pediatric Neuroradiology, University of California, San Francisco, San Francisco, CA USA.
authors: James
authors: J
authors: Barkovich
authors: Division of Gastroenterology, University of California, San Francisco, 1701 Divisadero, San Francisco, CA 94115 USA.|Hereditary GI Cancer Prevention Program, Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA USA.
authors: Jonathan P
authors: JP
authors: Terdiman
keywords: Adenomatous polyposis coli (APC); Emotional functioning; Familial adenomatous polyposis (FAP); Hereditary colon cancer; Neuropsychology