title: Prevalence, characteristics and clinical diagnosis of maturity onset diabetes of the young due to mutations in HNF1A, HNF4A, and glucokinase: results from the SEARCH for Diabetes in Youth.
abstract: OBJECTIVE
  Our study aims were to determine the frequency of MODY mutations (HNF1A, HNF4A, glucokinase) in a diverse population of youth with diabetes and to assess how well clinical features identify youth with maturity-onset diabetes of the young (MODY).
  
  
  METHODS
  The SEARCH for Diabetes in Youth study is a US multicenter, population-based study of youth with diabetes diagnosed at age younger than 20 years. We sequenced genomic DNA for mutations in the HNF1A, HNF4A, and glucokinase genes in 586 participants enrolled in SEARCH between 2001 and 2006. Selection criteria included diabetes autoantibody negativity and fasting C-peptide levels of 0.8 ng/mL or greater.
  
  
  RESULTS
  We identified a mutation in one of three MODY genes in 47 participants, or 8.0% of the tested sample, for a prevalence of at least 1.2% in the pediatric diabetes population. Of these, only 3 had a clinical diagnosis of MODY, and the majority was treated with insulin. Compared with the MODY-negative group, MODY-positive participants had lower FCP levels (2.2 ± 1.4 vs 3.2 ± 2.1 ng/mL, P < .01) and fewer type 2 diabetes-like metabolic features. Parental history of diabetes did not significantly differ between the 2 groups.
  
  
  CONCLUSIONS
  In this systematic study of MODY in a large pediatric US diabetes cohort, unselected by referral pattern or family history, MODY was usually misdiagnosed and incorrectly treated with insulin. Although many type 2 diabetes-like metabolic features were less common in the mutation-positive group, no single characteristic identified all patients with mutations. Clinicians should be alert to the possibility of MODY diagnosis, particularly in antibody-negative youth with diabetes.
authors.affiliation: MD, Department of Pediatrics/Division of Endocrinology, A5902, Seattle Children's Hospital, 4800 Sand Point Way NE, Seattle, Washington 98105. catherine.pihoker@seattlechildrens.org.
authors.forename: Catherine
authors.initials: C
authors.lastname: Pihoker
authors.forename: Lisa K
authors.initials: LK
authors.lastname: Gilliam
authors.forename: Sian
authors.initials: S
authors.lastname: Ellard
authors.forename: Dana
authors.initials: D
authors.lastname: Dabelea
authors.forename: Cralen
authors.initials: C
authors.lastname: Davis
authors.forename: Lawrence M
authors.initials: LM
authors.lastname: Dolan
authors.forename: Carla J
authors.initials: CJ
authors.lastname: Greenbaum
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Imperatore
authors.forename: Jean M
authors.initials: JM
authors.lastname: Lawrence
authors.forename: Santica M
authors.initials: SM
authors.lastname: Marcovina
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Mayer-Davis
authors.forename: Beatriz L
authors.initials: BL
authors.lastname: Rodriguez
authors.forename: Andrea K
authors.initials: AK
authors.lastname: Steck
authors.forename: Desmond E
authors.initials: DE
authors.lastname: Williams
authors.forename: Andrew T
authors.initials: AT
authors.lastname: Hattersley
mesh_terms: D000293:Adolescent; D017668:Age of Onset; D002648:Child; D002675:Child, Preschool; D004252:DNA Mutational Analysis; D003924:Diabetes Mellitus, Type 2 / Q000175:diagnosis* / Q000453:epidemiology / Q000235:genetics; D005260:Female; D005941:Glucokinase / Q000235:genetics*; D051538:Hepatocyte Nuclear Factor 1-alpha / Q000235:genetics*; D051557:Hepatocyte Nuclear Factor 4 / Q000235:genetics*; D006801:Humans; D008297:Male; D009154:Mutation; D015995:Prevalence; D055815:Young Adult
chemical_list: C496487:HNF1A protein, human; C496592:HNF4A protein, human; D051538:Hepatocyte Nuclear Factor 1-alpha; D051557:Hepatocyte Nuclear Factor 4; D005941:Glucokinase