title: Association of BMPR1A polymorphism, but not BMP4, with kidney size in full-term newborns.
abstract: BACKGROUND
  A correlation between renal mass and nephron number in newborns allows the use of total kidney volume at birth as a surrogate for congenital nephron number. As the bone morphogenetic protein type 4 (BMP4), and its receptor type 1A (BMPR1A, ALK3), play an important role in renal development, we hypothesized that common, functional polymorphisms in their genes might be responsible for variation in kidney size among healthy individuals.
  
  
  METHODS
  We recruited 179 healthy full-term newborns born to healthy women. Kidney volume was measured sonographically. Total kidney volume (TKV) was calculated as the sum of left and right kidneys, and normalized for body surface area (TKV/BSA). Genomic DNA was extracted from umbilical cord blood leukocytes, and c.455T > C (rs17563) BMP4 and c.67 + 5659A > T (rs7922846) BMPR1A genotypes were identified by PCR-RFLP.
  
  
  RESULTS
  TKV/BSA in newborns carrying at least one A BMPR1A allele (AA + AT) was significantly reduced by approximately 13 % as compared with TT homozygous newborns (106.7 ± 21.5 ml/m(2) vs. 122.7 ± 43.8 ml/m(2), p < 0.02). No significant differences in TKV/BSA were found among newborns with different BMP4 genotypes.
  
  
  CONCLUSIONS
  Results suggest that rs7922846 BMPR1A polymorphism may account for subtle variation in kidney size at birth, reflecting congenital nephron endowment.
authors.affiliation: Department of Clinical and Molecular Biochemistry, Pomeranian Medical University, ul. Powstancow Wlkp. 72, 70-111 Szczecin, Poland. mariush@pum.edu.pl
authors.forename: Mariusz
authors.initials: M
authors.lastname: Kaczmarczyk
authors.forename: Iwona
authors.initials: I
authors.lastname: Goracy
authors.forename: Beata
authors.initials: B
authors.lastname: Loniewska
authors.forename: Anna
authors.initials: A
authors.lastname: Kuprjanowicz
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Binczak-Kuleta
authors.forename: Jeremy S
authors.initials: JS
authors.lastname: Clark
authors.forename: Andrzej
authors.initials: A
authors.lastname: Ciechanowicz
mesh_terms: D001830:Body Surface Area; D055415:Bone Morphogenetic Protein 4 / Q000235:genetics*; D052005:Bone Morphogenetic Protein Receptors, Type I / Q000235:genetics*; D016009:Chi-Square Distribution; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005865:Gestational Age; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D007231:Infant, Newborn; D007668:Kidney / Q000000981:diagnostic imaging*; D008297:Male; D009929:Organ Size; D010641:Phenotype; D011044:Poland; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D011446:Prospective Studies; D014463:Ultrasonography
chemical_list: C525809:BMP4 protein, human; D055415:Bone Morphogenetic Protein 4; C498211:BMPR1A protein, human; D052005:Bone Morphogenetic Protein Receptors, Type I