title: Prematurity and Genetic Testing for Neonatal Diabetes.
abstract: Hyperglycemia in premature infants is usually thought to reflect inadequate pancreatic development rather than monogenic neonatal diabetes. No studies, to our knowledge, have investigated the prevalence of monogenic forms of diabetes in preterm infants.
  
  
  
  We studied 750 patients with diabetes diagnosed before 6 months of age. We compared the genetic etiology and clinical characteristics of 146 preterm patients born <37 weeks and compared them with 604 born ≥37 weeks.
  
  
  
  A genetic etiology was found in 97/146 (66%) preterm infants compared with 501/604 (83%) born ≥37weeks, P < .0001. Chromosome 6q24 imprinting abnormalities (27% vs 12%, P = .0001) and GATA6 mutations (9% vs 2%, P = .003) occurred more commonly in preterm than term infants while mutations in KCNJ11 were less common (21 vs 34%, P = .008). Preterm patients with an identified mutation were diagnosed later than those without an identified mutation (median [interquartile range] 35 [34 to 36] weeks vs 31 [28 to 36] weeks, P < .0001). No difference was seen in other clinical characteristics of preterm patients with and without an identified mutation including age of presentation, birth weight, and time to referral.
  
  
  
  Patients with neonatal diabetes due to a monogenic etiology can be born preterm, especially those with 6q24 abnormalities or GATA6 mutations. A genetic etiology is more likely in patients with less severe prematurity (>32 weeks). Prematurity should not prevent referral for genetic testing as 37% have a potassium channel mutation and as a result can get improved control by replacing insulin with sulphonylurea therapy.
authors.affiliation: Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, United Kingdom; Institute of Child Health, University College London, London, United Kingdom;
authors.forename: Rachel E J
authors.initials: RE
authors.lastname: Besser
authors.affiliation: Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, United Kingdom;
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Flanagan
authors.affiliation: Faculty of Medicine, University of Southampton, Southampton, United Kingdom; University Hospital Southampton National Health Service Foundation Trust, Southampton, United Kingdom; and.
authors.forename: Deborah G J
authors.initials: DG
authors.lastname: Mackay
authors.affiliation: Faculty of Medicine, University of Southampton, Southampton, United Kingdom; University Hospital Southampton National Health Service Foundation Trust, Southampton, United Kingdom; and.
authors.forename: I K
authors.initials: IK
authors.lastname: Temple
authors.affiliation: Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, United Kingdom; National Institute for Health Research Exeter Clinical Research Facility, Royal Devon & Exeter National Health Service Foundation Trust, Exeter, United Kingdom.
authors.forename: Maggie H
authors.initials: MH
authors.lastname: Shepherd
authors.affiliation: Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, United Kingdom; National Institute for Health Research Exeter Clinical Research Facility, Royal Devon & Exeter National Health Service Foundation Trust, Exeter, United Kingdom.
authors.forename: Beverley M
authors.initials: BM
authors.lastname: Shields
authors.affiliation: Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, United Kingdom;
authors.forename: Sian
authors.initials: S
authors.lastname: Ellard
authors.affiliation: Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, United Kingdom; a.t.hattersley@exeter.ac.uk.
authors.forename: Andrew T
authors.initials: AT
authors.lastname: Hattersley
mesh_terms: D003922:Diabetes Mellitus, Type 1 / Q000175:diagnosis* / Q000235:genetics*; D005260:Female; D005819:Genetic Markers; D005820:Genetic Testing; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases / Q000175:diagnosis* / Q000235:genetics*; D008297:Male; D009154:Mutation
chemical_list: D005819:Genetic Markers