Much of evolutionary biology focuses on ultimate causation–identifying the evolutionary forces that have led the world to be as it is today, without much regard for the nuts and bolts of how organisms work. Much of molecular biology, on the other hand, focuses on proximate causation–understanding how the world works without much regard to how […]

Greg Mayer, filling in for Jerry Coyne, has a post up on a somewhat odd objection to the appointment of Francis Collins as director of NIH: that he’s a geneticist. The argument seems to be that diseases are complicated and not entirely genetic, and that Collins isn’t hip to non-genetic subtleties. To be frank, this […]

Online this week, Nature has published a genome-wide association study for response to treatment for chronic hepatitis C infection-the authors identify a polymorphism in an interleukin gene that is a strong predictor of how well an individual is able to clear the virus. Interestingly, the frequency of the polymorphism in different populations tracks the previously […]

A remarkable study published in Science this week identifies a rare mutation in the gene DEC2 which influences the duration of sleep in humans. The authors started with a family where patterns of short sleep (about 6 hours of sleep a night on non-workdays, versus ~8 hours for other people in the family) seemed to […]

There’s a nice post over at Genetic Future getting into the details of a recent paper using ABI SOLiD to resequence a human genome. The comments are quite instructive as well. For those not dealing with these sorts of technologies regularly, it can all seem a bit incomprehensible, but the outcome of these sorts of […]

The NY Times reports on a new paper calling into question the theory that the dog was first domesticated in East Asia. The evidence for an East Asian origin of dogs came from a study of mitochondrial DNA, which showed that dog populations in East Asia harbored more diversity than their counterparts in other parts […]

In recent years, the genetic mechanisms by which humans have generated massive phenotypic diversity in dogs have started to be uncovered. We now know, for example, much about the genetics of pigmentation in dogs, and a major gene controlling body size. This week, another phenotype–the short, stubby legs of some dog breeds (see right)–has been […]

So Francis Collins, as expected, will be nominated to be the next head of NIH. From the NY Times: [P]raise for Dr. Collins, 59, was not universal or entirely enthusiastic. Dr. Georges C. Benjamin, executive director of the American Public Health Association, called Dr. Collins’s selection a “reasonable choice.” I think that’s about right–this is […]

Nicholas Wade (guesting posting for John Tierney) points to a set of papers in this week’s Nature reporting large genome-wide association studies of schizophrenia. The main upshot of the papers is that variants in the MHC region influences susceptibility to schizophrenia. This region influences susceptibility to a number of autoimmune diseases, so the association is […]

One of the rationales advanced for the identification of common alleles that confer modest risk to a disease via genome-wide association studies is that these associations will lead to biological insight into the disease. Two papers published today represent an important first step towards this goal for a variant associated with colorectal cancer. Like many […]

So after my wingeing about the quality of genetic associations found through candidate gene studies, it’s only appropriate that I point to a fun candidate gene association study published this week in Nature. The interesting point here is that the organism isn’t humans, but rather baboons, and the phenotype is susceptibility to malaria. Briefly, the […]

In a recent post, I made a blanket statement that the vast majority of candidate gene association studies published in psychiatric genetics (actually, in nearly all fields of genetics) are wrong. I’m not just being offhandedly dismissive–below, I outline the statistical argument behind that claim. This discussion is cribbed almost verbatim from a discussion of […]

In 2003, Avshalom Caspi and colleagues published an influential article (Google Scholar lists it as having almost 2000 citations in 6 years) claiming that genetic variation in the seratonin transposter gene influences how people respond to traumatic events–the particular, in terms of risk of depression. For years, this has been the poster-child example of gene-environment […]

PLoS Genetics has a nice paper identifying copy-number polymorphism in the transcription factor SOX5 as the causal mutation leading to the pea-comb phenotype (the bottom panels on the right) in chickens. The mutation leads to more widespread expression of the gene at a particular developmental time point, which presumably represses comb formation. Labels: Genetics

Two papers in Nature Genetics report today that variation in KITLG is associated with development of testicular germ cell tumors. Regular readers of this site will recognize that gene name: KITLG is also one of the important loci contributing to differences in skin pigmentation between human populations. The authors are aware of this: As KITLG […]

Many readers have probably heard that the ACLU has sued Myriad Genetics for its patent on genetic testing on BRCA1/2 (these genes account overall for a small fraction of breast cancer cases, but for many of the strongly inherited cases). Many companies hold gene patents, so why sue Myriad? The answer is simple: in the […]

The New York Times has an interesting little piece on bones, including a description of the unsettling genetic disorder fibrodysplasia ossificans progressiva: When Harry Eastlack was 5 years old, he broke his left leg while out playing with his sister. The fracture failed to set properly, and soon his hip and knee had stiffened up […]

Based on the comments on my previous post, I’m going to lay out an argument which I find reasonable for sequencing studies in human disease: Let’s follow Goldstein’s back-of-the-envelope calculations: assume there are ~100K polymorphisms (assuming Goldstein isn’t making the mistake I attribute to him, this includes polymorphisms both common and rare) that contribute to […]

Just over two years ago, I wrote a brief post explaining why I find the “debate” about common variants versus rare variants in human medical genetics to be largely unhelpful. I concluded thusly, after explaining some of the rationale for looking for common variants that affect disease susceptibility: So am I then arguing in favor […]

Most readers are likely familiar with the classic “taming of the fox” experiment started by Dmitri Belyaev–starting with a wild silver fox, the group was able to quickly breed both a tame and hyper-aggressive line of animals. I was unaware that, concurrently with this experiment, that same group was also performing the same experiment on […]