DNA and You

Voices of the Infertile in the NY Times

Infertility, which in some cases can have a genetic cause, is a challenging obstacle for many couples.  A recent article by Karen Barrow, in the NY Times, focuses on the challenges faced by couples unable to conceive. 

An interactive feature associated with the article features the voices of several of women interviewed.

Rett Syndrome on Fox Show: "So You Think You Can Dance"

Tara Parker-Pope of the NY Times writes about an episode of the Fox reality show, "So You Think You Can Dance," in which Rett syndrome was featured.

For more on Rett Syndrome:

Rett Syndrome (MECP2-Related Disorders) GeneReview

International Rett Syndrome Foundation

Mandatory Waistline Measurement in Japan: Good Public Health Social Policy? Or Genetic Discrimination Against Fat People?

The NY Times has a really interesting piece on a new policy of mandatory waistline measurement in Japan.  With a goal of improving the public health, the government has established a state prescribed limit on male waistlines of 33.5 inches along with a limit of 35.4 inches for women...

No...I'm really not kidding.

Companies and local governments will apparently be required - under this new national law - to measure waistlines of those 40-74 years old during annual checkups.  Apparently, those not meeting the country's standard will be given dieting guidance if they do not meet the standard and do not lose the weight over 3 months (with subsequent escalation of the scrutiny and advice if folks are still too rotund at 6 months). 

Interestingly, the Japanese government intends to impose monetary penalties on entities (local governments and companies that fail to meet specific targets).

Although I am sure that the Japanese government has good intentions, this is a very interesting policy in light of the fact that obesity is a trait that can only be partially modified by behavioral change.  In other words, it is clear that obesity risk is to some extent a heritable trait, determined to some extent by one's genetic background, that can be difficult for some individuals to overcome.

Although this is an interesting and aggressive experiment aimed at reducing healthcare costs, it has the potential to result in further stigmatization of those affected by the obesity epidemic (something that is, no doubt, intended by the rule since it may result in public health benefits).  By imposing penalties on local governments and companies, the government is avoiding the appearance of discriminating against those with generous waistlines; however, this will create tremendous incentives on these entities to exert considerable pressure on individuals whose waists are over the limits. 

In sum, it's a bold social policy.  It may help with healthcare costs in the long-run, but is it genetic discrimination? 

What do you think?

COPD and Your Genes: New Study of Familial Risks for Chronic Obstructive Pulmonary Disease

Yesterday, at Cancer and Your Genes, I mentioned an interesting study assessing the degree to which survival in prostate cancer seems to run within families (and therefore may be genetic).  Some of the same authors, including Kari Hemminki, the lead author, also have a paper in the May 2008 issue of the Journal of Epidemiology and Community Health that assesses familial risks for chronic obstructive pulmonary disease (COPD) amongst siblings in Sweden.

The results basically showed that siblings of individuals with COPD had much higher risks of COPD themselves (Standardized Incidence Ratio [SIR] = ~4.6) as compared to spouses of individuals with COPD (SIR = ~1.6).  The fact that the SIR was much higher for sibling pairs than for spouses is consistent with genetics underlying at least some familial susceptibility to this disabling lung disease. 

Although there is a rare familial cause of COPD (alpha-antitrypsin deficiency), it seems unlikely that this would account for a significant fraction of the familial effect.  It will be interesting to see what we learn in the future about other genes underlying COPD risk--and also the extent to which they interact with a known environmental risk factor for this disease, smoking, which itself has a heritable component.  Very complicated!

Henry Louis Gates, Jr. Interviews James Watson at The Root

Kudos to my girlfriend for pointing me in the direction of this one.  It's worth a look:

• A conversation between Henry Louis Gates, Jr. and James Watson.
• An essay by Henry Louis Gates, Jr. about the interview: "The Science of Racism"
• Video from the interview.

What do you all think?

Is it heritable? A new series on twin studies.

Twin studies are one of the foundations of modern human genetics.  Researchers take advantage of a basic biological fact (that identical or monozygotic twins share essentially 100% of their genomes while fraternal or dizygotic twins share 50%) to study to what degree certain traits (disease risk, etc.) are heritable (i.e., how much of the disease risk is conferred by the genes versus the environment or just random events). 

Twin studies offer a very interesting window into human genetics and can often be extremely thought-provoking.  Here at DNA and You, I will periodically point out an interesting twin study as food for thought.

For example, it is commonly assumed that any familial effect on political party choice is environmental in nature, but these authors set out to look into this in further detail.  Basically the results suggest that although there is a modest effect of genetics on political party choice, this is probably conferred through intermediate genetic influences on attitudes about key political debates and other things like church attendance and social class.