1. Genetic risk factors for asthma, hay fever and eczemaRecently, a study in understanding the genetics behind allergic diseases has pinpointed more than 100 genetic risk factors for asthma, hay fever and eczema, which makes a huge breakthrough in science. Asthma, hay fever and eczema, though affecting different parts of the body, are similar at many levels and shared many genetic risk factors.
However, the thing that still puzzle the scientists the most is the location of those shared genetic risk factors in the genome. This is important as it helps to identify the specific genes – when not working properly – cause allergic condition. Then, it can potentially give us new clues on how to prevent or treat the disease.
In the study, the genomes of 360,838 people were analysed and 136 separate positions in the genome that are risk factors for developing allergic conditions were pinpointed. These 136 genetic risk factors influence whether the 132 nearby genes were switched on or off.
“We think that these genes influence the risk of asthma, hay fever and eczema by affecting how the cells of the immune system work,” remarked Dr Ferreira, lead of the study.
Moreover, the study also discovered that environmental factors, e.g. smoking, could affect whether these genes are switched on or off.
The researchers are in an attempt to find out potential treatments or drugs targeting specific genes, and could switch the genes on or off, depending on what is required. Several drugs, where the researchers believe could be targeted at some of these genes to treat allergies, have been identified and would be tested in the laboratory.
2. New genetic marker for schizophrenia
A recent study in Osaka University found a rare genetic variant, RTN4R, which may play a fundamental role in schizophrenia, a disease caused by disturbances in neural circuits.
RTN4R is a subunit of RTN4. It regulates axon regeneration and structural plasticity, which plays crucial role in neural circuits. Located at chromosome 22q11.2, which is a hotspot for schizophrenia – it may be a promising candidate gene for the disease.
In the study, the DNA of 370 schizophrenia patients were screened, and a single missense mutation, R292H, that changed the amino acid of RTN4 from arginine to histidine was found in two patients. Considering R292H is located in the domain of RTN4R that binds to ligands – a change in amino acid could greatly affect the function of RTN4.
In order to test for the possibility, the mutation was expressed in chick retinal cells, and a significant change in myelin-dependent axonal behaviour was observed. Through computer simulations, it was found that the mutation reduced the interaction between RTN4 and its partner protein, LINGO1. Therefore, it was said by the researchers that the rare variants could be the risk factors for schizophrenia.
“There is growing evidence that rare variants contribute to neurodevelopment diseases. The R292H mutation was not found in any existing databases. Our findings strengthen the evidence that rare variants could contribute to schizophrenia,” elaborated Yamashita, one of the authors of the study.
3. Genetic test enables detection of asymptomatic pancreatic cancers
Pancreatic cysts which can be detected through medical scan, could be either benign or cancerous. Thus, the need for surgical removal of the cysts has to be determined. “On the one hand, you never want to subject a patient to unneeded surgery. But, survival rates for pancreatic cancer are much better if it is caught before symptoms arise, so you also don’t want to ignore an early warning sign,” said the lead author of the study, Aatur D. Singhi, surgical pathologist in the University of Pittsburgh Medical Centre.
Recently, PancreaSeq, a rapid, sensitive test was introduced – to help physicians in determining the patients who need the surgery. In order to perform the test, a small amount of fluid has to be removed from the cyst. From that, 10 different tumour genes associated with pancreatic cancer can be tested.
In the study, 595 patients were tested. Follow-up data from 102 patients, whose cysts were surgically removed, was analysed to evaluate the accuracy of the PancreaSeq test. The results showed 100% accuracy in classifying patients who have pre-cancer sign and patients who have cysts, which could potentially progress to cancerous lesions. However, the test was found to be less accurate in identifying a less prevalent pancreatic cysts known as mucinous cystic neoplasm (MCN).
Although PancreaSeq did not identify any false positives in either cyst type, the results of the study may be biased by the choice of which patients had their cysts surgically removed. Therefore, continue evaluation of the test’s reliability is to be done on patients who do not have their cysts removed. Currently, an improved version of PancreaSeq that incorporates additional tumour genes associated with pancreatic cancer is undergoing rigorous clinical testing. MIMS
Gut flora in infants may impact predisposition to asthma, allergies and other illnesses
Genetic elements may influence schizophrenia development
Study discovers potential target for pancreatic cancer