Association of morbid obesity with FTO and INSIG2 allelic variants.
OBJECTIVE
To determine whether 2 single nucleotide polymorphisms (SNPs) in the obesity genes the fat mass and obesity associated gene (FTO) and the insulin induced gene 2 (INSIG2) are associated with class III, or morbid, obesity in patients undergoing bariatric weight loss operations.


METHODS
Retrospective analysis of genotype and clinical data.


METHODS
Large rural tertiary care health system.


METHODS
A total of 707 adult patients with a body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) of at least 40 undergoing open or laparoscopic Roux-en-Y gastric bypass operations for morbid obesity or its comorbid medical problems at Geisinger Medical Center, Danville, Pennsylvania.


RESULTS
The mean BMI in the predominantly white female cohort was 51.2. Approximately 21% of patients were homozygous for the FTO obesity SNP variant, 13% were homozygous for the INSIG2 obesity SNP variant, and 3.4% were homozygous for both. Mean BMIs in the groups homozygous for each of these genes were not significantly different from nonhomozygotes. However, FTO/INSIG2 double homozygotes and homozygote/heterozygote pairs had significantly higher BMIs than the other groups.


CONCLUSIONS
Increased BMI in morbid obesity is associated with a combination of FTO and INSIG2 SNPs.
Chu
Xin
X
Weis Center for Research, Geisinger Clinic, 100 N Academy Ave, Danville, PA 17822, USA.
Erdman
Robert
R
Susek
Meghan
M
Gerst
Heather
H
Derr
Kimberly
K
Al-Agha
Mouna
M
Wood
G Craig
GC
Hartman
Christina
C
Yeager
Stephanie
S
Blosky
Mary Ann
MA
Krum
Wanda
W
Stewart
Walter F
WF
Carey
David
D
Benotti
Peter
P
Still
Christopher D
CD
Gerhard
Glenn S
GS
D000293:Adolescent; D000328:Adult; D000368:Aged; D000483:Alleles; D000071516:Alpha-Ketoglutarate-Dependent Dioxygenase FTO; D050110:Bariatric Surgery; D005260:Female; D005838:Genotype; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics*; D008297:Male; D008565:Membrane Proteins / Q000235:genetics*; D008875:Middle Aged; D009767:Obesity, Morbid / Q000235:genetics* / Q000601:surgery; D020641:Polymorphism, Single Nucleotide; D011506:Proteins / Q000235:genetics*; D012189:Retrospective Studies; D012424:Rural Population
C467727:INSIG2 protein, human; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D011506:Proteins; D000071516:Alpha-Ketoglutarate-Dependent Dioxygenase FTO; C526492:FTO protein, human