title: Meta-analysis of genome-wide linkage studies in BMI and obesity.
abstract: OBJECTIVE
  The objective was to provide an overall assessment of genetic linkage data of BMI and BMI-defined obesity using a nonparametric genome scan meta-analysis.
  
  
  METHODS
  We identified 37 published studies containing data on over 31,000 individuals from more than >10,000 families and obtained genome-wide logarithm of the odds (LOD) scores, non-parametric linkage (NPL) scores, or maximum likelihood scores (MLS). BMI was analyzed in a pooled set of all studies, as a subgroup of 10 studies that used BMI-defined obesity, and for subgroups ascertained through type 2 diabetes, hypertension, or subjects of European ancestry.
  
  
  RESULTS
  Bins at chromosome 13q13.2- q33.1, 12q23-q24.3 achieved suggestive evidence of linkage to BMI in the pooled analysis and samples ascertained for hypertension. Nominal evidence of linkage to these regions and suggestive evidence for 11q13.3-22.3 were also observed for BMI-defined obesity. The FTO obesity gene locus at 16q12.2 also showed nominal evidence for linkage. However, overall distribution of summed rank p values <0.05 is not different from that expected by chance. The strongest evidence was obtained in the families ascertained for hypertension at 9q31.1-qter and 12p11.21-q23 (p < 0.01).
  
  
  CONCLUSIONS
  Despite having substantial statistical power, we did not unequivocally implicate specific loci for BMI or obesity. This may be because genes influencing adiposity are of very small effect, with substantial genetic heterogeneity and variable dependence on environmental factors. However, the observation that the FTO gene maps to one of the highest ranking bins for obesity is interesting and, while not a validation of this approach, indicates that other potential loci identified in this study should be investigated further.
authors: King's College London, Guy's, King's & St. Thomas' School of Medicine, London, United Kingdom.
authors: Catherine L
authors: CL
authors: Saunders
authors: Benedetta D
authors: BD
authors: Chiodini
authors: Pak
authors: P
authors: Sham
authors: Cathryn M
authors: CM
authors: Lewis
authors: Victor
authors: V
authors: Abkevich
authors: Adebowale A
authors: AA
authors: Adeyemo
authors: Mariza
authors: M
authors: de Andrade
authors: Rector
authors: R
authors: Arya
authors: Gerald S
authors: GS
authors: Berenson
authors: John
authors: J
authors: Blangero
authors: Michael
authors: M
authors: Boehnke
authors: Ingrid B
authors: IB
authors: Borecki
authors: Yvon C
authors: YC
authors: Chagnon
authors: Wei
authors: W
authors: Chen
authors: Anthony G
authors: AG
authors: Comuzzie
authors: Hong-Wen
authors: HW
authors: Deng
authors: Ravindranath
authors: R
authors: Duggirala
authors: Mary F
authors: MF
authors: Feitosa
authors: Philippe
authors: P
authors: Froguel
authors: Robert L
authors: RL
authors: Hanson
authors: Johannes
authors: J
authors: Hebebrand
authors: Patricia
authors: P
authors: Huezo-Dias
authors: Ahmed H
authors: AH
authors: Kissebah
authors: Weidong
authors: W
authors: Li
authors: Amy
authors: A
authors: Luke
authors: Lisa J
authors: LJ
authors: Martin
authors: Matthew
authors: M
authors: Nash
authors: Miina
authors: M
authors: Ohman
authors: Lyle J
authors: LJ
authors: Palmer
authors: Leena
authors: L
authors: Peltonen
authors: Markus
authors: M
authors: Perola
authors: R Arlen
authors: RA
authors: Price
authors: Susan
authors: S
authors: Redline
authors: Sathanur R
authors: SR
authors: Srinivasan
authors: Michael P
authors: MP
authors: Stern
authors: Steven
authors: S
authors: Stone
authors: Heather
authors: H
authors: Stringham
authors: Stephen
authors: S
authors: Turner
authors: Cisca
authors: C
authors: Wijmenga
authors: David A
authors: DA
authors: Collier
mesh_terms: D050154:Adiposity; D015992:Body Mass Index; D003920:Diabetes Mellitus / Q000235:genetics; D008040:Genetic Linkage; D015894:Genome, Human; D006801:Humans; D006973:Hypertension / Q000235:genetics; D009765:Obesity / Q000235:genetics*