title: ANDROGEN RECEPTOR CAG AND GGN REPEAT POLYMORPHISMS AND BONE MASS IN BOYS AND GIRLS.
abstract: BACKGROUND
  the human androgen receptor (AR) gene possesses two trinucleotide polymorphic repeats, (CAG and GGN) that affect the amount of AR protein translated. In this study, we genotyped these polymorphic tracts in a representative sample of Caucasian children (Tanner ≤ 5), 152 boys (11.5 } 2.6 yrs) and 116 girls (10.1 } 3.2 yrs) from Spain and investigated their association with bone mass.
  
  
  METHODS
  the length of CAG and GGN repeats was determined by PCR and fragment analysis. Body composition was assessed by dual energy x-ray absorptiometry (DXA). Individuals were grouped as CAG short (CAGS) if harboring repeat lengths of ≤ 21 and CAG long (CAGL) if CAG > 21. Moreover, subjects were grouped as GGN short (GGNS) if harboring repeat lengths of ≤ 23 and GGN long (GGNL) if GGN > 23.
  
  
  RESULTS
  in boys, significant differences in height, body mass, whole body bone mineral density (BMD) and content (BMC), upper extremities BMC, lower extremities BMC, femoral neck BMD, Ward's triangle BMC and BMD and lumbar spine BMD were observed between CAGS and CAGL groups (P < 0.05). Thus, upper extremities BMD differed between GGNS and GGNL groups. After adjusting for confounding variables, only upper extremities BMD between GGNS and GGNL groups remained significant (P < 0.05). No differences were observed in girls in any measured site in relation to either CAG or GGN polymorphisms length.
  
  
  CONCLUSIONS
  our results support the hypothesis that longer alleles of the AR CAG and GGN polymorphisms are associated with increased bone mass in prepubertal boys.
authors.affiliation: Department of Physical Education, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria. Research Institute of Biomedical and Health Sciences, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria.. amelia.guadalupe@gmail.com.
authors.forename: Lorena
authors.initials: L
authors.lastname: Rodríguez-Garcia
authors.affiliation: Department of Physical Education, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria. Research Institute of Biomedical and Health Sciences, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria.. amelia.guadalupe@gmail.com.
authors.forename: Jesus G
authors.initials: JG
authors.lastname: Ponce-Gonzalez
authors.affiliation: Research Institute of Biomedical and Health Sciences, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria. Department of Mathematics, Universidad de Las Palmas de Gran Canaria.. amelia.guadalupe@gmail.com.
authors.forename: Juan J
authors.initials: JJ
authors.lastname: González-Henriquez
authors.affiliation: Department of Biochemistry and Physiology, Universidad de Las Palmas de Gran Canaria. Canary Islands Cancer Research Institute (ICIC), Las Palmas de Gran Canaria (Canary Islands), Spain.. amelia.guadalupe@gmail.com.
authors.forename: Francisco G
authors.initials: FG
authors.lastname: Rodriguez-Gonzalez
authors.affiliation: Department of Biochemistry and Physiology, Universidad de Las Palmas de Gran Canaria. Canary Islands Cancer Research Institute (ICIC), Las Palmas de Gran Canaria (Canary Islands), Spain.. amelia.guadalupe@gmail.com.
authors.forename: Bonifacio N
authors.initials: BN
authors.lastname: Díaz-Chico
authors.affiliation: Department of Physical Education, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria. Research Institute of Biomedical and Health Sciences, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria.. amelia.guadalupe@gmail.com.
authors.forename: Jose A L
authors.initials: JA
authors.lastname: Calbet
authors.affiliation: Department of Physical Education, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria. Research Institute of Biomedical and Health Sciences, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria.. amelia.guadalupe@gmail.com.
authors.forename: José A
authors.initials: JA
authors.lastname: Serrano-Sanchez
authors.affiliation: Department of Physical Education, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria. Research Institute of Biomedical and Health Sciences, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria.. amelia.guadalupe@gmail.com.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Dorado
authors.affiliation: Department of Physical Education, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria.. amelia.guadalupe@gmail.com.
authors.forename: Amelia
authors.initials: A
authors.lastname: Guadalupe-Grau
mesh_terms: D015502:Absorptiometry, Photon; D000293:Adolescent; D001823:Body Composition / Q000235:genetics; D015519:Bone Density / Q000235:genetics; D001842:Bone and Bones / Q000033:anatomy & histology*; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D011110:Polymorphism, Genetic / Q000235:genetics*; D011944:Receptors, Androgen / Q000235:genetics*; D012727:Sex Characteristics; D018911:Trinucleotide Repeats / Q000502:physiology*
chemical_list: C410798:AR protein, human; D011944:Receptors, Androgen