Double Mastectomy: What We Know About BRCA Mutations and Breat Cancer


English: breast cancer surgery in 18. century ...

English: breast cancer surgery in 18. century Deutsch: Brustkrebschirurgie im 18. Jhd. (Photo credit: Wikipedia)

Dear Reader,

somehow I have the intention to publish this article, so, as it can be important for somebody here.

Curi56: Annamaria

Scooped by Dr. Stefan Gruenwald onto  Amazing Science
Angelina Jolie decided to go for a double mastectomy. She doesn’t have cancer yet, but like many women with breast cancer mutations, she had the radical surgery to lower her risk. Describing her decision as “My Medical Choice,” the 37-year-old actress revealed in an op-ed in the New York Times that she carries the BRCA1 gene mutation, which gives her an 87% risk of developing breast cancer at some point in her life. The abnormal gene also increases her risk of getting ovarian cancer, a typically aggressive disease, by 50%. To counteract those odds, Jolie wrote that she decided to have both her breasts removed. While radical, her decision to pre-empt any future cancer is a common one, and backed by studies. In 2010, Australian scientists found that women with the BRCA1 or BRCA2 mutations who chose to have preventive mastectomies did not develop breast cancer over the three-year follow-up. What’s more, since the genetic abnormalities increase the risk of ovarian cancer, women who had their ovaries and fallopian tubes removed also dramatically lowered their risk of developing ovarian or breast cancers. They were 89% less likely to develop ovarian cancer and 61% less likely to develop breast cancer over three years than their counterparts who did not have prophylactic surgery. Among the 250 study participants who underwent preventive mastectomies, none developed breast cancer during the study follow-up. Additionally, a patient’s surgical choice affected overall mortality rates, both cancer related and not: only 3 percent of surgery participants died at the time of the study follow-up versus 10 percent of those who avoided the surgery. And while the mutations are inherited – a mother with either aberration has a 50-50 chance of passing it on to her children – women who don’t get the mutation are not at increased risk of developing breast cancer, even if they belong to families with a history of the disease. Previous studies had suggested that women who did not have the mutations but had a mother or sister who did, could have up to a five times greater risk of developing different types of breast cancer, which led them to schedule frequent biopsies and even preventive mastectomies. The latest research, however, suggests that’s not necessarily the case. But the new study counters those findings, concluding that the risk of breast cancer in women from BRCA families, who do not carry the mutations themselves, are no higher than that of women in families with other types of breast cancer. The study involved more than 3,000 families with breast cancer, including nearly 300 who had the BRCA1 or BRCA2 mutations. The genetic test for the BRCA mutations isn’t done for every woman, or even for every woman who is at risk of developing breast cancer. Doctors recommend it for those who develop cancer at a young age, or have multiple family members with the disease. It’s expensive – up to $3000 – and insurers require that patients meet a threshold for needing the test before they cover its cost. Jolie is fortunate to be able to afford not just the test but the reconstructive surgery following the procedure as well. But she’s aware that not all women are even aware of the genetic screening and may not be able to afford the testing. She wrote that her goal in announcing her choice to remove her breasts prophylactically is to raise awareness of the test and the treatment options that women have if they are positive for the mutations.

How Blue Eyes Originated!


 

Close-up of a blue-eyed koala

Close-up of a blue-eyed koala (Photo credit: Wikipedia)

https://youtu.be/zPN6AGdGV0g

How Blue eyes Originated

Everyone with blue eyes alive today – from Angelina Jolie to Wayne Rooney – can trace their ancestry back to one person who probably lived about 10,000 years ago in the Black Sea region, a study has found. Scientists studying the genetics of eye colour have discovered that more than 99.5 per cent of blue-eyed people who volunteered to have their DNA analysed have the same tiny mutation in the gene that determines the colour of the Iris.

This indicates that the mutation originated in just one person who became the ancestor of all subsequent people in the world with blue eyes, according to a study by Professor Hans Eiberg and colleagues at the University of Copenhagen.

The scientists are not sure when the mutation occurred but other evidence suggested it probably arose about 10,000 years ago when there was a rapid expansion of the human population in Europe as a result of the spread of agriculture from the Middle East.

“The mutations responsible for blue eye colour most likely originate from the north-west part of the Black Sea region, where the great agricultural migration of the northern part of Europe took place in the Neolithic periods about 6,000 to 10,000 years ago,” the researchers report in the journal Human Genetics.

Professor Eiberg said that brown is the “default” colour for human eyes which results from a build-up of the dark skin pigment, melanin. However, in northern Europe a mutation arose in a gene known as OCA2 that disrupted melanin production in the iris and caused the eye colour to become blue.

“Originally, we all had brown eyes,” said Professor Eiberg. “But a genetic mutation affecting the OCA2 gene in our chromosomes resulted in the creation of a ‘switch’ which literally turned off the ability to produce brown eyes.”

Variations in the colour of people’s eyes can be explained by the amount of melanin in the iris, but blue-eyed individuals only have a small degree of variation in the amount of melanin in their eyes, he said.

“From this we can conclude that all blue-eyed individuals are linked to the same ancestor. They have all inherited the same switch at exactly the same spot in their DNA,” said Professor Eiberg.

Men and women with blue eyes have almost exactly the same genetic sequence in the part of the DNA responsible for eye colour. However, brown-eyed people, by contrast, have a considerable amount of individual variation in that area of DNA.

Professor Eiberg said he has analysed the DNA of about 800 people with blue eyes, ranging from fair-skinned, blond-haired Scandinavians to dark-skinned, blue-eyed people living in Turkey and Jordan.

“All of them, apart from possibly one exception, had exactly the same DNA sequence in the region of the OCA2 gene. This to me indicates very strongly that there must have been a single, common ancestor of all these people,” he said.

It is not known why blue eyes spread among the population of northern Europe and southern Russia. Explanations include the suggestions that the blue eye colour either offered some advantage in the long hours of daylight in the summer, or short hours of daylight in winter, or that the trait was deemed attractive and therefore advantageous in terms of sexual selection.

Source The Independent