Friday 30 May, 2014
On Friday evening at Hunter College, a panel of five (plus moderator) discussed the ethics of altering genes in embryos to avoid diseases. The conversation centered on mitochondrial transfer IVF, or so-called “Three-Parent IVF” (although as Nita Farahany, Genome Sciences and Policy lawyer, pointed out, it takes more than a bit of DNA to be a parent).
This technique enables women who carry mitochondrial disease to avoid passing it on to their children. The nucleus of the mother’s egg is transferred to that of a donor with normal mitochondria (the donor egg’s nucleus having been removed). Just as in conventional IVF, the egg is then fertilized by the father’s sperm before being transferred to the uterus.
So far no human baby has been born as a result of mitochondrial transfer IVF, but embryos have been successfully formed. Paula Amato, who is working on this technique in Oregon, said that women are lining up to do it, and that FDA approval is being sought.
However FDA regulations have become stricter, and as Jamie Grifo (a fertility specialist at NYU) said, if today’s regulations had been in place 35 years ago, Louise Brown would never have been born, and ICSI (intra-cytoplasmic sperm injection) and PGD (pre-implantation genetic diagnosis) would not be available. Dr Grifo emphasized the need to practice empathy when deciding what techniques can and cannot be provided to patients. He felt that people who don’t understand the science are making regulatory decisions, and that in the end the patients suffer.
According to Dr Farahany, a major reason for public resistance to these technologies is the history of the US Eugenics movement, which advocated enforced sterilization to prevent the breeding of, for example, “imbeciles” and criminals. However, these practices became illegal and clear boundaries were set. While Sheldon Krimsky (Philosopher of Science and Bioethicist) was skeptical of society’s ability to set ethical boundaries, Dr Farahany felt that we need to trust society more, and argued that we can shift the line and create new ethical boundaries as new technologies emerge. As others on the panel pointed out, whenever new technologies emerge there are public fears.
A quick show of hands from the audience revealed that the vast majority were in favor of allowing mitochondrial transfer IVF to be used in patients. We will have to wait and see whether the FDA agrees.
Saturday 31 May, 2014
Mary-Claire King, discoverer of the BRCA1 breast cancer gene, is a geneticist at the University of Washington. She was honored at this year’s World Science Festival for her pioneering work.
Analyzing family trees, Dr King discovered that mutations in the BRCA1 gene are inherited, and predispose carriers to breast and ovarian cancer. The main gene mutation is a two base-pair deletion, or frame-shift, which she elegantly described thus; Genetics is written in 3 letter words, ‘the fat cat ate the rat.’ If two of the letters in a word are removed, the sentence becomes nonsense; ‘the fca tat eth era t.’
If a woman inherits a mutated BRCA1 allele, and then the epithelial cells lining her breast ducts or ovaries develop a second mutated BRCA1 allele, she is highly likely to develop breast or ovarian cancer. Women known to have inherited one mutated BRCA allele can undergo regular mammograms starting at a younger age to try to detect cancer earlier, or receive chemoprevention to reduce the risk of cancer.
Prophylactic mastectomy (as done recently by Angelina Jolie), or salpingo-oophorectomy (removal of fallopian tubes and ovaries), in high-risk patients are also options. However, they are obviously far from desirable for many women.
Worryingly, in recent years younger women have been found to be getting breast cancer, probably due to improved detection methods, but also changes in diet and exercise, earlier age at menarche, and later first pregnancies. In Dr King’s words, breast cancer is unique in being “a cancer of well-being.”
However, we don’t want to undo the well being, we want to work out how to prevent the disease.
So should BRCA testing be available to all women? It potentially enables women to make decisions which could save their lives. Furthermore, it is technically feasible, the costs are coming down, it is non-invasive (requiring just a routine blood draw), and only needs to be done once.
Dr King’s emphatic answer to that question is: Yes, because if not now, when? What more do we need to know in order to do it? She said it is already being done by the “elites” who have access and can afford it, but that it needs to be available across the board. Judging from the audience’s reaction, that was a popular sentiment.