TBC1D1 is a candidate for a severe obesity gene and evidence for a gene/gene interaction in obesity predisposition.
The molecular etiology of obesity predisposition is largely unknown. Here, we present evidence that genetic variation in TBC1D1 confers risk for severe obesity in females. We identified a coding variant (R125W) in TBC1D1 that segregated with the disease in 4p15-14-linked obesity pedigrees. In cases derived from pedigrees with the strongest linkage evidence, the variant was significantly associated with obesity (P=0.000007) and chromosomes carrying R125W accounted for the majority of the evidence that originally linked 4p15-14 with the disease. In addition, by selecting families that segregated R125W with obesity, we were able to generate highly significant linkage evidence for an obesity predisposition locus at 4q34-35. This result provides additional and confirming evidence that R125W affects obesity susceptibility, delimits the location of an obesity gene at 4q34-35 and identifies a gene/gene interaction that influences the risk for obesity predisposition. Finally, although the function of TBC1D1 is unknown, the protein is structurally similar to a known regulator of insulin-mediated Glut4 translocation.
Stone
Steven
S
Myriad Genetics, Inc., Salt City, UT 84108, USA. sstone@myriad.com
Abkevich
Victor
V
Russell
Deanna L
DL
Riley
Robyn
R
Timms
Kirsten
K
Tran
Thanh
T
Trem
Deborah
D
Frank
David
D
Jammulapati
Srikanth
S
Neff
Chris D
CD
Iliev
Diana
D
Gress
Richard
R
He
Gongping
G
Frech
Georges C
GC
Adams
Ted D
TD
Skolnick
Mark H
MH
Lanchbury
Jerry S
JS
Gutin
Alexander
A
Hunt
Steven C
SC
Shattuck
Donna
D
D002894:Chromosomes, Human, Pair 4 / Q000235:genetics; D010450:Endopeptidases / Q000235:genetics*; D005260:Female; D015870:Gene Expression; D014644:Genetic Variation; D006239:Haplotypes; D006801:Humans; D015810:Linkage Disequilibrium; D008126:Lod Score; D008297:Male; D009765:Obesity / Q000209:etiology / Q000235:genetics*; D015513:Oncogene Proteins / Q000235:genetics*; D010375:Pedigree; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014018:Tissue Distribution; D043222:Ubiquitin Thiolesterase
D015513:Oncogene Proteins; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D010450:Endopeptidases; C473330:USP6 protein, human; D043222:Ubiquitin Thiolesterase