title: Novel Leptin Receptor Mutations Identified in Two Girls with Severe Obesity Are Associated with Increased Bone Mineral Density.
abstract: BACKGROUND
  Recessive mutations in the leptin receptor (LEPR) are a rare cause of hyperphagia and severe early-onset obesity. To date, the phenotype has only been described in 25 obese children, some of whom also had altered immune function, hypogonadotropic hypogonadism, reduced growth hormone secretion, hypothalamic hypothyroidism or reduced adult height. We provide a detailed description of the phenotype of 2 affected girls to add to this knowledge.
  
  
  METHODS
  Whole-exome sequencing and targeted sequencing were used to detect the LEPR mutations. RNA analysis was performed to assess the effect of splice-site mutations.
  
  
  RESULTS
  In 2 unrelated girls with severe obesity, three novel LEPR mutations were detected. Longitudinal growth data show normal childhood growth, and in the older girl, a normal adult height despite hypogonadotropic hypogonadism and the lack of an obvious pubertal growth spurt. Bone age is remarkably advanced in the younger (prepubertal) girl, and bone mineral density (BMD) is high in both girls, which might be directly or indirectly related to leptin resistance.
  
  
  CONCLUSIONS
  The spectrum of clinical features of LEPR deficiency may be expanded with increased BMD. Future observations in LEPR-deficient subjects should help further unravel the role of leptin in human bone biology.
authors.affiliation: Department of Paediatrics, Willem Alexander Children's Hospital, Leiden, The Netherlands.
authors.forename: Sabine E
authors.initials: SE
authors.lastname: Hannema
authors.forename: Jan M
authors.initials: JM
authors.lastname: Wit
authors.forename: Mieke E C A M
authors.initials: ME
authors.lastname: Houdijk
authors.forename: Arie
authors.initials: A
authors.lastname: van Haeringen
authors.forename: Elsa C
authors.initials: EC
authors.lastname: Bik
authors.forename: Annemieke J M H
authors.initials: AJ
authors.lastname: Verkerk
authors.forename: André G
authors.initials: AG
authors.lastname: Uitterlinden
authors.forename: Sarina G
authors.initials: SG
authors.lastname: Kant
authors.forename: Wilma
authors.initials: W
authors.lastname: Oostdijk
authors.forename: Egbert
authors.initials: E
authors.lastname: Bakker
authors.forename: Henriette A
authors.initials: HA
authors.lastname: Delemarre-van de Waal
authors.forename: Monique
authors.initials: M
authors.lastname: Losekoot
mesh_terms: D000293:Adolescent; D000328:Adult; D015519:Bone Density; D002648:Child; D005260:Female; D006801:Humans; D009154:Mutation; D009765:Obesity / Q000097:blood / Q000235:genetics* / Q000473:pathology; D054411:Receptors, Leptin / Q000235:genetics* / Q000378:metabolism; D012720:Severity of Illness Index
chemical_list: D054411:Receptors, Leptin