Consumer Genetics

There is a good letter in "Nature", 26.8.2010 by Christopher Kanan, discussing consumer genetics:

Consumers have a right to affordable genetic testing

There is no good reason for people to have access to their personal genetic information only through medical experts, as Arthur Beaudet suggests (Nature 466, 816–817; 2010). Such tests provide an incentive for consumers to learn about genetics and to support genetics research, while encouraging them to make reasonably informed decisions about their health.

Consumers have a right to acquire affordable information about their genetic profile. Independent studies could verify the quality of the data gathered, and this could easily be done by product-review organizations such as the US-based Consumers Union.

Regulating the quality of data interpretation would be harder, especially because data-inference models improve over time. Companies should explain that their models for interpreting genetic material are probabilistic and imperfect. They should also reference the studies used to generate these models and allow users to download the uninterpreted data.

Some companies warn consumers that they should not change their lifestyle if they learn they have a higher risk of a disease. But if a test indicates that a person's risk of developing heart disease is above average, they may exercise more and eat better. Is this any worse than changing your behaviour because your father died of heart disease?

Beaudet suggests that ancestry tests may be acceptable with limited regulation, but that using the same genetic material to infer health-related information should have medical approval. Why should one type of genetic test be acceptable and the other not? Consumers may make life-altering decisions based on that information in both cases, but the fear that this information will harm them is speculative.

Because some genetic tests may have to compete with less expensive, direct-to-consumer products, people calling for a ban on such tests should declare any competing financial interests.

Caution is recommended - but basically the information about his own genetic heritage should be free for everyone and should be given without much paternalism.

Human traits and their evolution - a new book

The OMIM-databank ("Online Mendelian Inheritance in Man") is full of scientific literature concerning data and theories about the evolutionary causes of the worldwide distribution (frequencies) of inborn human traits - of EVERY inborn human trait, we know about today. Only very few popular science books exist today, that try to give the public an understanding at least of the tip of the iceberg, that is formed by that databank - that is humanity's knowledge about itself. So a lot of reason exist to welcome books, that are publicised in that field. We have to thank "Gene Expression" once more for giving a hint to a new book in this field:

A review of Survival of the Sickest, by Sharon Moalem with Jonathan Prince

(...)

Most of the chapters are centered around the population genetics of a disease. This is fascinating material, and Moalem (along with his co-author) does a wonderful job presenting it. Each chapter starts with an observation--a high prevalance of Type I diabetes in Europeans, the frequency of a genetic disease called hemochromatosis, or the geographic distribution of favism, for example--which sets the stage for a series of anecdotes that eventually leads the reader to his evolutionary hypothesis (for the examples given, these hypotheses are adaptation to cold and resistance to the plague and malaria, repectively). Some of these anecdotes are worth the price of the book alone (though, it must be noted, I didn't pay for my copy, so I suppose I can't judge)--there's an investigation of the biology of a toad that allows itself to freeze solid each winter that is particularly remarkable, and the section on host manipulation by parasites would make Carl Zimmer proud. A large number of human traits are touched on from this perspective--apart from the ones mentioned above, traits like skin color, alcoholism, taste, and even skull shape get mentions[1].

While these chapters are the highlight of the book, an alert reader may notice a couple hints that perhaps the science isn't definitive on some of these stories: first, the oft-added qualifier that a given theory (for example, that the high rate of hypertension in African-Americans is due to selection for salt retention on slave boats) is "controversial", and second, that there are a number of theories for some of the observations. The prevalence of diabetes, for instance, is attributed to metabolic systems unaccustomed to carbohydrate-rich diets (pg. 26), a selective sweep for better cold response during the Younger Dryas (pg. 46), and transgenerational epigentic effects, the so-called "thrifty phenotype" hypothesis (pg. 166). These possibilities are not mutually exclusive, but a reconciliation of all of them would certainly have been desirable.

(...)

[1] Moalem gives a cursory look at the concept of "race" with regard to these traits, but essentially chooses not to discuss it, preferring to cite a Nature Genetics editorial from 2001 as saying that "population clusters identified by genotype analysis seem to more informative than those identified by skin color or self-declaration of race". Regular readers know that much has changed since 2001; in particular, there doesn't seem to be much of a distinction between genetic clusters and clusters based on self-declaration of race [Tang et al. 2005].