Aurora magazine

Biliary atresia is a disease that affects the bile ducts, or the channels that carry bile from the liver to the intestine. It occurs already in the neonatal age and causes the reflux of bile into the liver, causing cirrhosis and yellowing of the skin. The fibrous tissue in the ducts blocks the bile flowing into the liver, further damaging the organ. The disease affects about one in 20,000 newborns, especially girls. Although the causes are genetic, it is not a hereditary disease except in very rare cases. Usually the atresia occurs between the second and sixth week of life.

The newborn has yellow skin, an enlarged liver and a swollen abdomen. The urine is dark and the stools are clear. All these symptoms are also present in other liver diseases, which makes the diagnosis more laborious. Before talking about atresia it is necessary to perform laboratory tests that exclude other pathologies. At this point ultrasounds are used to measure the size of the bile ducts. For the moment, the only treatment for biliary atresia is surgery.

The doctor creates a drainage of bile from the liver, so as to replace the blocked ducts. For this purpose we use a piece of intestine taken from the child himself. If all goes well, the jaundice disappears and the child returns to feel good at least for some time. You can follow a fairly normal diet, with due care. Unfortunately the operation is successful only in 50% of cases.

In the case of reduced bile flow, the child must reduce fat as much as possible. He must also take vitamin supplements, given that one of the tasks of bile is to absorb these substances. Even in the best cases, liver damage tends to continue its course and cause cirrhosis. At this point all that remains is liver transplantation.

Source: paginemediche.it

Since 2013, several international teams have been studying how to use CRISPR against Duchenne dystrophy. For now, the therapy has been shown to work on guinea pigs with the disease. When is experimentation on humans? The researchers talked about it during the XVII International Conference on Duchenne and Becker muscular dystrophy.

The gene responsible for dystrophy is very cumbersome, which makes gene therapy more complicated. Transporting a healthy copy to sick cells using the usual viruses is impossible. As a result, scientists are developing different alternatives to classical gene therapy. However, all this work requires a large number of experiments, above all to understand what the impact on human beings could be.

There are currently three alternative gene therapies being developed.

1. Modify the expression of the gene responsible for the disease.
2. Act only on deletion mutations, those in which a stroke is missing.
3. In case of duplication mutations, remove too many portions.

For the time being, only 13 human patients have tested gene therapies in progress. The results seem positive for the moment, but the analyzes and tests are still in progress. Furthermore, only one treatment has been approved so far and could only help a slice of the sick. It works only on patients with a particular genetic mutation, not on the others.

The Italian Giulio Cossu offered an alternative to CRISPR during the conference. With his Manchester University team he is testing stem cell transplantation. The treatment is still under study.

Source: lescienze.it

A small retrospective study has identified a typical genetic variant of a certain pancreatic cancer. Some patients with a particular pancreatic duct lesion have the same hereditary mutation. Researchers believe this variant could contribute to the development of the tumor. Consequently, by identifying it in time, we could intervene with much more specific treatments.

The discovery comes from the team of Dr. Nicholas Roberts, of the Johns Hopkins University School of Medicine. The aim was to verify the presence of inherited mutations among those at risk of cancer. Thus the role of genetics in the development of a specific type of pancreatic cancer, pancreatic ductal adenocarcinoma has emerged. The form of cancer studied is the third most lethal in the United States. The 5-year survival rate is around 8% and tumors develop from non-invasive lesions. In particular, about 70% of the pancreatic duct lessons become malignant, but how it is still unclear.

According to the study, about 5% of patients with these lesions are carriers of the same genetic mutation. The team of researchers examined the DNA of non-tumor duct lesions, taking the tissue from 315 patients. They have sequenced 94 genes in search of mutations associated with cancer risk. Of the patients, 23 had the same mutation in one or two genes; 9 patients had the mutation in a gene linked to pancreatic cancer.

Comparing the data with those of the incidence of the tumor, it was found that the mutation in three specific genes is linked to a higher rate of pancreatic ductal adenocarcinoma. Patients with this hereditary mutation are more likely to get sick than those who do not.

Source: hopkinsmedicine.org

An Australian mother gave birth to a pair of "almost identical" twins, born of an oocyte and two spermatozoa. This is the second case in the world, the first identified during pregnancy. The case, more unique than rare, was followed by Dr. Michael Gabbett of Queensland University of Technology in Australia.

According to the scientists, two spermatozoa fertilized the oocyte together, before it split up. At first, gestation seems a normal case of homozygous twins: fetuses share the same placenta. Yet at the 14th week it emerges that one child is male and the other is female: it is impossible for them to be homozygous. The identical twins, in fact, share the same DNA and therefore the same genus. When the two spermatozoa fertilized the oocyte, three sets of chromosomes were found.

Usually this event is incompatible with life and the embryos do not survive. In this case, however, the chromosomes split into two and gave rise to a pair of twins. All the cells contain the chromosomes of the mother, some contain those of the first spermatozoon and others those of the second. The twins therefore have a very similar but not identical DNA.

Source: theguardian.com