Genetics & Molecular Biology

University of Iowa researchers have learned more about a genetic mutation that contributes to autism. The mutation occurred in sperm cells of a father, who does not have autism, but passed the condition on to two of his children. The investigators now know more about how the mutation causes problems with a specific gene and are testing for additional mutations of the same gene in other people with autism. Thomas Wassink, M.D., associate professor of psychiatry in the UI Carver College of Medicine, is presenting the findings May 3 at the annual International Meeting for Autism Research in…

Last fall I had a chance to hear a presentation by Doug Berg, a microbiologist here at Washington University. Berg's work is a great combination of new technology, genomics and evolution, and it happens to also have potential medical relevance. He's studying the evolution of drug resistance in Helicobacter pylori, a usually benign bacterium that is responsible for stomach ulcers. (Recall that the Nobel Prize in medicine was awarded in 2005 to Barry Marshall and Robin Warren for their discovery of the link between H. pylori and ulcers.) Berg is basically evolving highly drug resistant…

Traditionally, the genome has been viewed as a collection of DNA molecules that vary in composition between individuals and species, and variations that generate phenotypic differences have been assumed to occur in a more or less random manner. More recently, this view has been challenged by evidence that genomes are in fact reservoirs of adaptive phenotypic plasticity. This adaptive genome concept, where mutations that convey adaptive benefits are likely to occur at greater than random frequencies (Caporale 1999, 2000, 2003) represents a synthesis of ideas and evidence from several…

Just recently Science published the paper describing the latest primate genome - the rhesus macaque genome. (Check out Science's macaque website for some good (and free) articles on the subject.) Sequencing a large genome like this one is resource intensive (unlike microbial genomes, which are now easily and routinely sequenced), so why did scientists sequence yet another primate genome? In addition to the human genome we already have the chimp genome, and we also have several non-primate mammalian genomes - the mouse, rat, cow, dog, and opossum genomes. Is this a good use of our money?…

The largest study to date of genetic variation among chimpanzees has found that the traditional, geography-based sorting of chimps into three populations—western, central and eastern—is underpinned by significant genetic differences, two to three times greater than the variation between the most different human populations. In the April 2007 issue of the journal PLOS Genetics, researchers from the University of Chicago, Harvard, the Broad Institute and Arizona State show that there has been very little detectable admixture between the different populations and that chimps from the central…

Researchers have discovered that the genetic malfunction that causes a form of mental retardation called Noonan Syndrome (NS) produces an imbalance in the genesis of two types of cells in the developing embryonic brain. This imbalance, they theorize, could explain how the genetic abnormality gives rise to the neural pathology of the disorder. More broadly, they said, the new insight into the mechanism underlying NS could apply to other inherited forms of retardation. NS is a relatively common genetic disorder, occurring in one of every 2,500 live births. It is characterized by congenital…

For the growing number of people with diminished immune systems - cancer patients, transplant recipients, those with HIV/AIDS - infection by a ubiquitous mold known as Aspergillus fumigatus can be a death sentence. The fungus, which is found in the soil, on plant debris and indoor air, is easily managed by the healthy immune system. But as medical advances contribute to a growing population of people whose immune systems are weakened by disease or treatment, the opportunistic fungus poses a serious risk. Now, however, scientists may have found a master switch, an über gene, that seems to…

I rubbed the belly of the Gene Genie , and it revealed unto me that I shall search the OMIM database with the term "nine". So, let's venture into the unknown expanse of the human genome (cue some Carl Sagan space documentary music). Oh, this one looks good: #201250 ACROMESOMELIC DYSPLASIA, HUNTER-THOMPSON TYPE. Maybe this will be the gene associated with confrontational writing skills and the ability to ingest copious quantities of illicit drugs. But alas no. Acromesomelic Dysplasia, Hunter-Thompson type, a.k.a. AMDH or Acromesomelic dwarfism, is a rare autosomal recessive form of dwarfism…

I was thinking about how us humans have 25,000 or so genes, and I know nothing about 99.9% of them. And I call myself a molecular geneticist! Wouldn't it be nice to know a little more about the strands of DNA that play a big part in making up who we are? I think it would be, so I'm going to start a semi-frequent excersion into the human genome and invite any willing blog readers to join with me. There are all kinds of databases just brimming with all kinds of info, so where is a poor boy to start? For some reason, I've always had an aversion to human genetics and disease genes. Don't ask me…

Genetics tests could help provide cystic fibrosis (CF) patients with targeted treatment in future, pilot study authors suggest. Results from a French clinical trial published today in BMC Medicine show how a small percentage of CF sufferers with a rare genetic stop mutation responded positively to gentamicin treatment. Aleksander Edelman and Isabelle Sermet-Gaudelus of Faculté de Médicine Necker in Paris led collaborators from several French institutions studying how the antibiotic gentamicin affected CF patients with a stop mutation. The team used a dual reporter gene assay first in vitro…