Press releases
Please quote Nature Genetics as the source of these items.
The January 2007 issue of Nature Genetics is available online.
January 2007
Malaria parasite diversity
Three studies independently characterize the genetic diversity of the parasite that causes malaria in the January issue of Nature Genetics.
Two of the studies focus on Plasmodium falciparum, the most deadly of the Plasmodium species known to cause human malaria, while one study also compares it to the related Plasmodium reichenowi, which infects chimpanzees. Overall, these data constitute a valuable resource that should improve understanding of drug resistance in malaria, as well as identifying candidate targets for vaccines.
Dyann Wirth and colleagues present a genome-wide map of diversity in P. falciparum, including full genome sequencing of 16 new and geographically diverse strains, and targeted sequencing of an additional 54 worldwide isolates. In an accompanying study, Xin-zhuan Su, Philip Awadalla and colleagues focus on sequencing of genomic regions coding for proteins within 4 P. falciparum isolates. They sequenced approximately 3,500 genes, representing about 19% of the genome, develop a high-resolution map of genetic variation, and report 7 new candidate targets for vaccines. In the third study, Manolis Dermitzakis, Matthew Berriman and colleagues provide the first sequence of the P. reichenowi strain, as well as the sequence of two P. falciparum strains, and examine the evolutionary differences between the two. One of the P. falciparum strains, a new uncultured clinical isolate from an individual from Ghana, may provide a better model than strains cultured in the laboratory.
Genome-wide variation and identification of vaccine targets in the Plasmodium falciparum genome
Jianbing Mu, Philip Awadalla, Junhui Duan, Kate M McGee, Jon Keebler, Karl Seydel, Gilean A T McVean & Xin-zhuan Su
Published online: 10 December 2006 | doi 10.1038/ng1924
A genome-wide map of diversity in Plasmodium falciparum
Sarah K Volkman, Pardis C Sabeti, David DeCaprio, Daniel E Neafsey, Stephen F Schaffner, Danny A Milner Jr, Johanna P Daily, Ousmane Sarr, Daouda Ndiaye, Omar Ndir, Soulyemane Mboup, Manoj T Duraisingh, Amanda Lukens, Alan Derr, Nicole Stange-Thomann, Skye Waggoner, Robert Onofrio, Liuda Ziaugra, Evan Mauceli, Sante Gnerre, David B Jaffe, Joanne Zainoun, Roger C Wiegand, Bruce W Birren, Daniel L Hartl, James E Galagan, Eric S Lander & Dyann F Wirth
Published online: 10 December 2006 | doi 10.1038/ng1930
Genome variation and evolution of the malaria parasite Plasmodium falciparum
Daniel C Jeffares, Arnab Pain, Andrew Berry, Anthony V Cox, James Stalker, Catherine E Ingle, Alan Thomas, Michael A Quail, Kyle Siebenthall, Anne-Catrin Uhlemann, Sue Kyes, Sanjeev Krishna, Chris Newbold, Emmanouil T Dermitzakis & Matthew Berriman
Published online: 10 December 2006 | doi 10.1038/ng1931
Lightning strikes twice for milk drinkers
The ability of Africans and Europeans to digest milk as adults is a textbook example of a trait arising independently in two populations in response to the same strong selective pressure. This ability — known as lactase persistence — is analyzed in the January issue of Nature Genetics.
Lactase persistence is frequent in Northern European populations, but much lower elsewhere, and may have become established as a consequence of cattle domestication and a pastoralist lifestyle. Previous work had shown that genetically, it could be attributed to variants that control the expression of the gene encoding the enzyme lactase-phlorizin hydrolase (LPH). This enzyme breaks down lactose into more easily absorbed sugars such as glucose and galactose.
Sarah Tishkoff and colleagues asked whether the genetic basis of lactase persistence in certain pastoralist populations in East Africa might be attributed to the same variants. They studied 470 lactase-persistent and lactase non-persistent individuals from Kenya, Tanzania, and Sudan and found a significant association between lactase persistence and one variant that is very close in location to the LPH variant previously associated with the trait in Europeans. Because other genetic markers in the region differed between the two populations, the authors conclude that the lactase persistent-associated LPH variants arose independently.
Convergent adaptation of human lactase persistence in Africa and Europe
Sarah A Tishkoff, Floyd A Reed, Alessia Ranciaro, Benjamin F Voight, Courtney C Babbitt, Jesse S Silverman, Kweli Powell, Holly M Mortensen, Jibril B Hirbo, Maha Osman, Muntaser Ibrahim, Sabah A Omar, Godfrey Lema, Thomas B Nyambo, Jilur Ghori, Suzannah Bumpstead, Jonathan K Pritchard, Gregory A Wray & Panos Deloukas
Published online: 10 December 2006 | doi 10.1038/ng1946
Genetic mutation in autism identified
A gene called SHANK3 is mutated in a small number of individuals with autism, providing new insight into the biological basis of this disease, according to a study to be published in the January issue of Nature Genetics.
Autism spectrum disorders (ASD), which comprise a range of disorders affecting social interaction and communication, affect 6 out of every 1,000 children. Approximately 3–6% of cases are caused by chromosomal rearrangements, with a small region on chromosome 22 affected frequently in individuals with cognitive deficits accompanied by autistic behavior. This region contains three genes, one of which — SHANK3 — is a good candidate to be associated with autism given its expression in neuronal synapses.
Thomas Bourgeron and colleagues sequenced SHANK3 in more than 200 individuals with ASD, and found mutations in 3 families. An individual in one family had a significant deletion in the gene, while two brothers in a second family had a smaller deletion. In the third family, a girl with autism had a deletion in SHANK3, while her brother, affected with a mild form of autism called Asperger syndrome, had an additional copy of SHANK3. The protein encoded by SHANK3 interacts with other proteins called neuroligins, which have a role in neuronal signaling. Mutations in two of the genes encoding neuroligins have previously been found in a small number of individuals with autism, suggesting that neuroligin function should receive increased attention in the search for the biological basis of ASD.
Mutations in the gene encoding the synaptic scaffolding protein SHANK3 are associated with autism spectrum disorders
Christelle M Durand, Catalina Betancur, Tobias M Boeckers, Juergen Bockmann, Pauline Chaste, Fabien Fauchereau, Gudrun Nygren, Maria Rastam, I Carina Gillberg, Henrik Anckarsäter, Eili Sponheim, Hany Goubran–Botros, Richard Delorme, Nadia Chabane, Marie–Christine Mouren–Simeoni, Philippe de Mas, Eric Bieth, Bernadette Rogé, Delphine Héron, Lydie Burglen, Christopher Gillberg, Marion Leboyer & Thomas Bourgeron
Published online: 17 December 2006 | doi 10.1038/ng1933
New genetic cause of an immunodeficiency syndrome found
A gene called HAX1 is mutated in some individuals with an immunodeficiency syndrome known as severe congenital neutropenia (SCN), according to a study to be published in the January issue of Nature Genetics. The identification of mutations in HAX1 ends a 50-year search for the genetic basis of one form of this disease.
SCN comprises a group of disorders characterized by low levels of neutrophils in peripheral blood and bone marrow. As neutrophils are part of the body’s defense against bacteria, affected individuals can develop life-threatening infections without treatment. The recessive form of SCN is also called Kostmann disease, after its discoverer, who identified it in 1956.
Christoph Klein and colleagues have now identified mutations in HAX1 in three Kurdish families and 19 other unrelated individuals with recessive SCN. The HAX1 protein is found in mitochondria, the energy-producing compartments of the cell, and the authors show that it is required to maintain viable neutrophils. Although recessive SCN is rare, the authors suggest that individuals with this or other forms of SCN may have mutations in other genes that normally promote the survival of neutrophils.
HAX1 deficiency causes autosomal recessive severe congenital neutropenia (Kostmann disease)
Christoph Klein, Magda Grudzien, Giridharan Appaswamy, Manuela Germeshausen, Inga Sandrock, Alejandro A Schäffer, Chozhavendan Rathinam, Kaan Boztug, Beate Schwinzer, Nima Rezaei, Georg Bohn, Malin Melin, Göran Carlsson, Bengt Fadeel, Niklas Dahl, Jan Palmblad, Jan-Inge Henter, Cornelia Zeidler, Bodo Grimbacher & Karl Welte
Published online: 24 December 2006 | doi 10.1038/ng1940
