News briefs

Genes found linked to autism and intellectual disability

Researchers from the University of Adelaide have helped identify 91 genes, 38 of which are completely new, linked to autism and intellectual disabilities. Most of the gene mutations (65%) were inherited, suggesting not all of them were sufficient on their own to cause disease. The researchers had hoped data from 11 730 cases would allow them to distinguish between genes linked to autism and those linked to intellectual disability, but found that most of the 91 genes were affected in both conditions. Only eight gene mutations linked to autism were not present in the group with intellectual disabilities, while 17 mutations linked to intellectual disabilities were absent in the group with autism. The researchers also found that the pattern of mutations in high functioning autism differs from the pattern seen in autism with intellectual disability — an important finding for diagnostic, prognostic and therapeutic reasons, said the authors. The study, published in Nature Genetics, commenced in 2009 and was conducted with the support of an international consortium, the Autism Spectrum/Intellectual Disability network. The network involves 15 centres across seven countries and four continents; 11 730 autism spectrum disorder, intellectual disability and developmental disability cases were tested and, from these, 2383 cases with intellectual disability came from Adelaide.

Dormant breast stem cells linked to pregnancy growth

Researchers from Walter and Eliza Hall Institute have used advanced imaging technology to find a long-lived type of breast stem cell that is responsible for the growth of the mammary glands during pregnancy, enabling lactation. The newly discovered stem cells, which respond to progesterone and oestrogen, may also be linked to a high risk form of breast cancer. The discovery was made by Dr Nai Yang Fu, Dr Anne Rios, Professor Jane Visvader and Professor Geoff Lindeman as part of a 20-year research program into how the breast develops from stem cells and how breast cancers can arise from stem cells and developing breast tissue. The research has been published in Nature Cell Biology. The research also revealed that the stem cells with high levels of two proteins called tetraspanin8 and Lgr5 have many similarities to a subtype of “triple negative” breast cancers known as claudin-low cancers. “Compared to other types of breast cancer, claudin-low cancers have a high chance of recurrence after treatment, leading to a poor prognosis for patients,” Professor Visvader said.