title: The distribution of exon 3-deleted/full-length growth hormone receptor polymorphism in the Turkish population.
abstract: OBJECTIVE
  The exon 3-deleted/full-length (d3/fl) growth hormone receptor (d3/fl-GHR) polymorphism has been associated with responsiveness to GH therapy in some children and also with adult height variation in the general population. We aimed to evaluate the distribution of d3/fl-GHR polymorphism in a Turkish population.
  
  
  METHODS
  The study included 477 (54 females/423 males) healthy adults with a mean±SD age of 31.1±9.0 years (range: 18-57). Height and body mass index (BMI) were expressed as standard deviation score (SDS) according to national standards. All adults had normal height and BMI SDSs (between -2 and +2). GHR exon 3 isoforms were studied by simple multiplex polymerase chain reaction method. Insulin-like growth factor-1 (IGF-1) and IGF-binding protein-3 (IGFBP-3) values were also measured and expressed as SDS.
  
  
  RESULTS
  The distribution of the GHR exon 3 genotypes in the Turkish healthy adults was 35% (n=167) for fl/fl, 39% (n=186) for fl/d3, and 26% (n=124) for d3/d3. There was no difference between genders in GHR exon 3 genotypes. Frequencies of fl allele and d3 allele were 54.5% and 45.5%, respectively. There were no differences in height SDS and BMI SDS among the three d3/fl-GHR genotype groups. There was a significant difference in IGFBP-3 SDS between fl/fl and fl/d3 groups (p=0.022).
  
  
  CONCLUSIONS
  This study presents the results of GHR polymorphism in a Turkish population as a reference for further studies. The distribution was similiar to European populations. There were no correlations between GHR isoforms and height SDS or other clinical/biochemical characteristics of the individuals except for higher IGFBP-3 levels in the fl/d3 group as compared to the fl/fl group. Whether this finding implies an abnormality, needs further investigation.
authors.affiliation: Istanbul University Istanbul Faculty of Medicine, Pediatric Endocrinology Unit, Istanbul, Turkey. firdevsb@istanbul.edu.tr
authors.forename: Firdevs
authors.initials: F
authors.lastname: Baş
authors.forename: Fatih
authors.initials: F
authors.lastname: Keleşoğlu
authors.forename: Özlem
authors.initials: Ö
authors.lastname: Timirci
authors.forename: Sema
authors.initials: S
authors.lastname: Kabataş Eryılmaz
authors.forename: Nilüfer
authors.initials: N
authors.lastname: Bozkurt
authors.forename: Banu
authors.initials: B
authors.lastname: Küçükemre Aydın
authors.forename: Rüveyde
authors.initials: R
authors.lastname: Bundak
authors.forename: Turgay
authors.initials: T
authors.lastname: Isbir
authors.forename: Feyza
authors.initials: F
authors.lastname: Darendeliler
mesh_terms: D000293:Adolescent; D000328:Adult; D000483:Alleles; D001827:Body Height / Q000235:genetics; D004247:DNA / Q000737:chemistry / Q000235:genetics; D005091:Exons; D005260:Female; D017353:Gene Deletion; D014644:Genetic Variation; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000235:genetics; D007334:Insulin-Like Growth Factor I / Q000235:genetics; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D011986:Receptors, Somatotropin / Q000235:genetics*; D014421:Turkey; D055815:Young Adult
chemical_list: C515497:IGFBP3 protein, human; D018972:Insulin-Like Growth Factor Binding Protein 3; D011986:Receptors, Somatotropin; D007334:Insulin-Like Growth Factor I; D004247:DNA