The FTO gene

We watched the BBC Horizon programme on genetic causes of obesity, fronted by Dr Giles Yeo (good to see an ethnic East Asian presenter).

Dr Giles Yeo with some of the AA variant folk

There is a gene of quite large effect; here is what Wikipedia says:

"A study of 38,759 Europeans for variants of FTO identified an obesity risk allele. In particular, carriers of one copy of the allele weighed on average 1.2 kilograms (2.6 lb) more than people with no copies.

"Carriers of two copies (16% of the subjects) weighed 3 kilograms (6.6 lb) more and had a 1.67-fold higher rate of obesity than those with no copies.

"The association was observed in ages 7 and upwards. "

...

"In adult humans, it was shown that adults bearing the at risk AT and AA alleles at rs9939609 consumed between 500 and 1250 kJ more each day than those carrying the protective TT genotype (equivalent to between 125 and 280 kcal per day more intake).

"The same study showed that there was no impact of the polymorphism on energy expenditure. This finding of an effect of the rs9939609 polymorphism on food intake or satiety has been independently replicated in five subsequent studies (in order of publication)."

The protective allele is T while the risk allele is A at SNP site rs9939609.

---

Here is what 23andMe says about my late mother, Beryl Seel, and myself.

My mother had the protective genotype, TT, and was never overweight; I'm not so lucky (AT) and had to fight to get my weight down to its current 70-71 kilograms (from 86kg in mid-2012).

We can infer that my late father, who definitely had an expanded waistline, was AT or AA. Based on family history and if pressed, I would guess AT .. and that I got unlucky.

I wrote about this 18 months ago: another Horizon programme.