Aurora magazine

On July 28, 2017, Charlie Gard, the British kid with mitochondrial DNA depletion syndrome died. It is a rare genetic disease that causes the progressive decline of DNA in mitochondria. Since mitochondria are the organelles that give energy to the cells, the muscles lose weight slowly and lead to death.
There is a chromosome in the DNA that produces only 13 proteins. Despite being few, each of these is necessary for the proper functioning of mitochondria. Inside the mitochondria there are then about 1,000 protein chains encoded by genes of nuclear DNA.

In decomposing mitochondrial DNA, some nuclear genes work badly. Malfunction leads to DNA leakage from mitochondria. Mitochondria therefore lose the ability to produce energy and the organs that are affected are the ones that consume more. Muscles, liver and brain, left uncharged, stop functioning.
The symptoms of mitochondrial diseases are very heterogeneous, but the most common are muscle weakness and difficulty in feeding. Various forms of the disease have in common the early manifestation, which takes place in the early days or months of life. In these cases the symptoms worsen rapidly. Progression, on the other hand, is slower in later forms.

Mutations that cause mitochondrial DNA depletion are recessive. For the disease to manifest, it is necessary to inherit the mutated gene from both parents. The diagnosis takes place with a targeted examination, which serves to quantify mitochondrial DNA. To this is added the genetic test, which allows to identify the mutation.

To date there is no cure and only treatments exist to mitigate the symptoms.

Source: repubblica.it

Uterine fibroids are benign tumors that affect 70% of women within 50 years. About 1 out of 4 women in reproductive age experience symptoms, including very painful menstruation. Causes are genetic factors, with steroid hormones and growth factors added. According to a study, intramural fibrosis may interfere with the fertility and success of IVF.

Depending on the type of fibroma, the effects on female fertility also change. The uterine myomas distort the uterine cavity, increasing the risk of infertility and spontaneous abortion. Subconscious fibers that grow out of the uterus, however, do not seem to have any adverse effects on reproduction. The role of intramural fibrosis is much more controversial. The study evaluated the impact of these on IVF.

The study involved 163 women with intramural fibroids that did not distort the cavity. All concerned were scheduled for IVF procedures. They were accompanied by a 326-woman non-fibrous-free control group. The researchers injected all of the first dose of hormone to stimulate follicles. Some implanted embryos after 3 days, and others after 5 days.

The pregnancy rate was 32.5% in the first group, compared with 42.6% in the second group. The rate of live births in women with fibroids was 26.9%, compared with 37.4% in the other. The percentage of live births has been almost unchanged among women with 1 fibroma and 2 or more fibroids. The percentage of pregnancies has changed significantly.

The smaller fibers of 3 cm were not associated with a significant negative impact. Those over 3 cm instead had a very important impact on IVF outcomes. The cause is unclear, as intramural fibroids do not affect the shape of the uterus. Surgical removal causes scarring and delayed the onset of fertilization treatments. All this without increasing the number of pregnancies significantly.

Source: medscape.com

Researchers at the University of Israel have shown that Western men have less sperm than before. They analyzed the data of 7,500 studies, focusing on the interpretations of another 185 conducted between 1973 and 2011. In recent decades, sperm concentration decreased by 52.4%, with a decrease in the total sperm count of 59.3%.

The study found a significant decline only in North America, Europe, Australia and New Zealand. On the other hand, there was no significant change in South America, Asia and Africa. It must be said, however, that there are many less studies for this second group of countries. So there is a picture that is far from reassuring: fertility in the western world is undergoing a stop.

According to the authors, it is important to identify the causes of the decline as soon as possible. One of the most likely causes is exposure to chemicals, even in prenatal ages. The decline in fertility is also due to a change in lifestyle in recent years. Western men are more susceptible to stress and pollution. Also, many of them are overweight and smoke.

Source: indiatoday.intoday.in

With the advancement of new DNA analysis technologies, prenatal screening tests are also refining. Today, just a drop of maternal blood to check if the fetus suffers from Down's syndrome or other genetic abnormalities. Instead, other tests should be done before conceiving and identifying possible mutations that are dangerous to the offspring.
What are the genetic tests that are changing the world of prenatal screening?

Free circulating fetal DNA testing
Maternal blood also contains a certain amount of cells from the fetus. By recovering these it is possible to analyze its DNA in the first weeks of gestation. These tests are safe for both mom and baby and have a high level of reliability.

Free fetal DNA tests are used to identify common chromosomal abnormalities, such as Down's syndrome. They are especially recommended for older couples and give a much earlier response to traditional tests. Nevertheless, in case of a positive result, it is advisable to use the amniocentesis, too.

Widened bearer screening

In the past, the history was the only way to test for the presence of genetic diseases in the family. Even today it is a key element in deciding whether and which genetic tests to perform. The tests also focused on a particular set of abnormalities. This made it impossible to identify any variants linked to different pathologies.

Extended bearer screening is a wide-ranging genetic test that identifies variants of over 100 diseases. To do just that, you need a blood sample for each couple member. If the same anomaly emerges in both, then there is the risk that the offspring will manifest the disease. It is estimated that this is about 5% of the couples who undergo screening.

Sequencing the Exam
In some rare cases, ultrasonography reveals malformations in the fetus that can not be diagnosed with traditional genetic testing. Sequencing of the next generation is focused on developmental and health related genes. For this reason it is also useful for assessing the health of the fetus and can provide a diagnosis in 30% of the cases.
Unlike invasive prenatal diagnosis, this requires amniocentesis. Even though it has a minimal risk, it is possible to intervene immediately at birth.

Source: huffingtonpost.com