title: Pathologic lower extremity fractures in children with Alagille syndrome.
abstract: OBJECTIVE
  : In this retrospective study, we aimed to determine the incidence and distribution of fractures in patients with Alagille syndrome, 1 of the leading inherited causes of pediatric cholestatic liver disease.
  
  
  METHODS
  : Surveys regarding growth, nutrition, and organ involvement were distributed to patient families in the Alagille Syndrome Alliance of the Children's Hospital of Philadelphia research database. Patients with a history of fracture were identified by their response to 1 question, and details characterizing each patient's medical, growth, and fracture history were obtained through chart review and telephone contact.
  
  
  RESULTS
  : Twelve of 42 patients (28%) reported a total of 27 fractures. Patients experienced fractures at a mean age of 5 years, which contrasts with healthy children, in whom fracture incidence peaks in adolescence. Fractures occurred primarily in the lower extremity long bones (70%) and with little or no trauma (84%). Estimated incidence rate calculations yielded 399.6 total fractures per 10,000 person-years (95% confidence interval 206.5, 698.0) and 127.6 femur fractures per 10,000 person-years (95% confidence interval 42.4, 297.7). There were no differences in sex, age distribution, or organ system involvement between the fracture and no-fracture groups.
  
  
  CONCLUSIONS
  : Children with Alagille syndrome may be at risk for pathologic fractures, which manifest at an early age and in a unique distribution favoring the lower extremity long bones. Although this preliminary study is limited by small sample size and potential ascertainment bias, the data suggest that larger studies are warranted to further characterize fracture risk and explore factors contributing to bone fragility in these children.
authors.affiliation: Department of Pediatrics, The Department of Biostatistics and Epidemiology at the University of Pennsylvania School of Medicine, Philadelphia, PA, USA.
authors.forename: Christina B
authors.initials: CB
authors.lastname: Bales
authors.forename: Binita M
authors.initials: BM
authors.lastname: Kamath
authors.forename: Pedro S
authors.initials: PS
authors.lastname: Munoz
authors.forename: Alexander
authors.initials: A
authors.lastname: Nguyen
authors.forename: David A
authors.initials: DA
authors.lastname: Piccoli
authors.forename: Nancy B
authors.initials: NB
authors.lastname: Spinner
authors.forename: David
authors.initials: D
authors.lastname: Horn
authors.forename: Justine
authors.initials: J
authors.lastname: Shults
authors.forename: Mary B
authors.initials: MB
authors.lastname: Leonard
authors.forename: Adda
authors.initials: A
authors.lastname: Grimberg
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Loomes
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D016738:Alagille Syndrome / Q000150:complications* / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D005260:Female; D005598:Fractures, Spontaneous / Q000209:etiology* / Q000235:genetics; D006306:Health Surveys; D006801:Humans; D015994:Incidence; D007223:Infant; D035002:Lower Extremity / Q000293:injuries*; D008297:Male; D012189:Retrospective Studies; D012307:Risk Factors; D055815:Young Adult
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