Genetics Refresher

by Dr. Hsien-Hsien Lei
Posted July 30, 2009 in DNA in General

After being semi-out of it for the past year, I think I could use a refresher on genetics. Luckily, the National Human Genome Research Institute (NHGRI) has it covered with fact sheets about the Institute, genetics and biology, and ethical, legal, and social implications research.

I think I’ll start with:

• DNA Chip Technology
• Genome-Wide Association Studies (GWAS)
• Genetic Information Nondiscrimination Act of 2008

HT: National DNA Day Facebook page

(>> Start a discussion!)

Biopolis Street, Singapore

by Dr. Hsien-Hsien Lei
Posted July 27, 2009 in DNA Around the World

One of the coolest places in Singapore – Biopolis, centre for biomedical sciences in Asia.

The Genome building houses swissnex Singapore (previously Swiss House Singapore) and the Genome Institute of Singapore.

(>> Start a discussion!)

Overweight Parents, Overweight Children

by Dr. Hsien-Hsien Lei
Posted July 14, 2009 in DNA and Disease

Seems like I’m stating the obvious, doesn’t it? Of course parents have a huge impact on whether their children become overweight. They buy whatever food is in the home and model eating habits. These preferences, however, are most likely partly genetic and partly behavioral.

In David Kessler’s new book, The End of Overeating, he discusses how serotonin and dopamine work to increase our cravings and appetite. Both genes and conditioning contribute to the levels of these neurotransmitters in our brain.

The interaction between genes and behavior is difficult to tease apart. A recent study has found that the behaviors of obese parents may be more to blame than the genes they’ve passed on to their children.

The EarlyBird Diabetes Study looked at 226 British families and found that :

• Obese mothers are 10 times more likely to have obese daughters
• Obese fathers are 6 times more likely to have obese sons
• There is no association between obese mothers and obese sons, obese fathers and obese daughters

The Study’s Director, Professor Terry Wilkin said:

Any genetic link between obese parents and their children would be indiscriminate of gender. The clearly defined gender-assortative pattern which our research has uncovered is an exciting one because it points towards behavioural factors at work in childhood obesity.

But don’t count out genetics! What about imprinting? Genomic imprinting results in exactly this sort of pattern in which genes are expressed differently depending on the parent of origin, mother or father.

Regardless, there is no question that obesity rates in developed countries have increased tremendously. In The End of of Overeating, Dr. Kessler makes the case that it’s because the food industry knows exactly how to alter food chemistry and layer fat, sugar, and salt to make food super-palatable. So even though our genes may not have changed that much in the last half century, the foods that we have ready access to certainly have. Just think what life must have been like before McDonald’s was founded in 1940!

In our family the pattern observed in the study seems to be holding true. My son takes after his svelte father while my daughter tends towards the chubbier side. Considering I am feeding them all, I suggest that genes and how they influence what and how much we eat are still important. That doesn’t excuse my tendency to indulge, though. As with everything to do with parenting, time to reconsider what kind of example I’m setting for my kids.

News.com.au, ScienceDaily

Edited 28 Jul 2009 to clear up misstatement about imprinting.

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