Table 1.

Studies on FTO gene polymorphisms in children and adolescents

Children and adolescents	FTO: rs9939609 variant		Reference
	A-allele effect in adiposity or energy intake	main effect
7,477 UK children from the ALSPAC cohort (7–11 years) and 4,320 children from the NFBC1966 cohort (14 years)	BMI z-score increase per A-allele: 0.08 kg/m2; p = 3 × 10–5 (7 years) 0.12 kg/m2; p = 7 × 10–9 (11 years) 0.05kg/m2; p = 0.04 (14 years)	obesity risk per A-allele: 1.35; p = 6 × 10–4 (11 years) 1.36; 95% CI (1.17–1.57) (14 years)	Frayling et al., 2007 [10]
450 severely obese Swedish children (232/218 w/m, 12 years) and 512 normal weight controls (268/244 w/m, 17 years)	BMI z-score increase per A-allele: 0.2–0.5 kg/m2; p = 0.0343	obesity risk for AA genotype: 1.59; 95% CI (1.11–2.27); p = 0.016	Jacobsson et al., 2008 [31]
3,337 UK children from TEDS: a population-based twin cohort. Case-control from SCOOP-UK (926 obese), and ALSPAC (4,022 normal weight control subject) cohorts (7–11 years)	BMI z-score increase per A-allele: 0.13–0.18 kg/m2; p < 0.001 WC increase per A-allele: 0.60–0.95 cm; p < 0.001 AA homozygotes had reduced satiety responsiveness scores (p = 0.008)	overweight/obesity risk for A-allele: 1.76; 95% CI (1.59–1.94); p = 9 × 10–28	Wardle et al., 2008 [39]
4,318 UK children (10–13 years) from the ALSPAC study	fat mass increase per A-allele: 0.68 ± 0.25 kg (13 years) No association with DED	greater fat mass independently of DED	Johnson et al., 2009 [38]
97 Scottish children (4–10 year)	A-allele carriers: 1.78 kg greater fat mass; p = 0.01 the A-allele was associated with higher energy intake (p = 0.006) independently of body weight	confirm the association with BMI and greater fat mass	Cecil et al., 2008 [40]
3,589 children from UK from the ALSPAC study (10–11 years).	total energy intake increase per A-allele: 1.01 kcal/day; p = 0.03 total fat intake increase per A-allele: 1.01 g/day; p = 0.02	significant association with total fat and energy intake after adjustment for BMI	Timpson et al., 2008 [37]

	Other FTO variants, main effect
700 lean children and 283 obese children from France, Germany and Switzerland.	C allele for rs1421085 was significantly associated (p = 0.01) with increased BMI z-score		Dina et al., 2007 [11]
450 obese Swedish (6–21 years) and 512 normal weight Swedish (15–20 years).	no association between c.896+223A>G variant and BMI z-score; obese subjects with GG genotype had increased fasting serum insulin levels (p = 0.017) and insulin resistance (p = 0.025)		Jacobsson et al., 2008 [35]
ALSPAC = Avon Longitudinal Study of Parents and Children; NFBC1966 = Northern Finland 1966 Birth Cohort; TEDS = Twins’ Early Development Study; SCOOP-UK = Severe Childhood Onset Obesity Project UK; DED=dietary energy density; w/m=women/men.