The Human Fertilization and Embryology Authority - Britain's regulatory body for reproductive and genetic technologies - has just given the green light for IVF embryos to be screened for the "breast cancer genes". Two couples, whose families have histories of breast cancer, will be permitted to use pre-implantation genetic diagnosis (PGD) to screen out embryos carrying the BRCA1 and BRCA2 gene mutations before going forward with assisted reproduction.

This is part of the HFEA's recent lowering of the bar in expanding PGD's use. Initially, the HFEA approved PGD only in limited circumstances: (1) when genes are certain to lead to disease, not merely probable (2) when the disease is early onset and (3) when it is almost always fatal. Remarkably, the HFEA changed course last year, stating it would consider PGD for hereditary cancers on a case-by-case basis. The mutations that have now been approved for PGD are associated with a 60% of female children eventually developing breast cancer - much lower than the HFEA's original standards.

But besides this dropping bar, this also highlights two roles played by government in promoting what some call a "new eugenics."

Many defenders of using today's biotechnologies to improve the human gene pool accurately cite a key difference with 20th century eugenics: decisions now ultimately lie with individuals, not the state. Yet here with the HFEA's loosening its PGD rules, we are witnessing a widely-respected government agency approving the deselection of genes that have about a fifty-fifty chance of causing disease, which only the females could develop, not to mention the growing number of therapies to treat people with these conditions.

Moreover, the ability to detect breast cancer genes was developed with public funds at the University of Utah, a public university. While no coercive laws mandate the deselection of certain embryos, saying that government is not involved here in weeding out undesirable embryos is like saying the government had not role in the recent deaths from Vioxx. Government action is not merely limited to writing laws, but also funding certain types of research and regulating (or failing to) certain areas of commercial activity such as assisted reproduction.

The Innocence Project, a public interest litigation shop dedicated to using DNA evidence to free wrongly convicted prisoners, recently reached a remarkable milestone: its 200th exoneration. This application of human biotechnology is certainly an unqualified good; falsely convicted inmates in 31 states - 14 of whom were on death row - have been reunited with their families. And in 43 cases the real assailant was found.

Barry Scheck, the Project's co-founder, zealously supports using DNA forensics in criminal justice, noting that "we have a technology (DNA) that is a truth machine." Scheck's passion is admirable; we should all celebrate the Innocence Project's success and hope for more. But we must also be careful to distinguish the positive use of DNA technologies - in this case for exoneration purposes - from applications that support DNA databanks and dragnets, which trounce basic civil liberties by treating us all like felons under constant government surveillance. It may be tempting to use these 200 stories to justify broadening the use of DNA forensics in criminal justice. Yet we must remain vigilant to ensure that the key used to unlock these former prisoners' shackles isn't used to unjustly lock away others.

Don Imus' slanderous comments and the Duke lacrosse players' dropped rape charges have moved race back into America's consciousness. But another case that may very well come to represent the future of racial conflict is quietly making its way through the New York State Supreme Court. Nancy and Thomas Andrews (pictured above) are suing a Park Avenue fertility clinic for botching the IVF procedure leading to their second daughter's birth (Jessica, pictured between the couple).

According to DNA tests, the clinic mistakenly fertilized Nancy's egg with sperm from someone other than her husband.Assisted reproduction errors like this are certainly unfortunate, though not entirely unprecedented. But what's extraordinary here is that a significant part of the Andrews' lawsuit sought relief not simply for the mixup, but for the specific "harm" inflicted by having a "black child."

The Andrews argue that had the procedure gone as planned, Jessica would not only have been related to both of them but would also have a lighter skin tone similar to their first daughter (pictured above to the far right). Jessica's darker skin suggests to the Andrews that her biological father is someone of African descent.

The Andrews make no bones about their particular disappointment with Jessica's skin color, having described their anguish in the lawsuit:

• "We underwent a difficult and complex medical procedure for the sole purpose of bearing a child of our own."
• "While we love Baby Jessica as our own, we are reminded of this terrible mistake each and every time we look at her."
• "We fear that our daughter will be the object of scorn and ridicule by other children, both in school and as she grows up."
• "She may be subjected to physical and emotional illness as a result of not being the same race as her parents and siblings."

There's certainly a lot going on here. But what strikes me most is that despite their disappointment in Jessica's color, Nancy is curiously dark herself. She is a native of the Dominican Republic - a nation with a strong African heritage. While sensational headlines such as "Black Baby is Born to White Pair" might sell papers, what gets lost is how genes express themselves differently in each person.

Put differently, it's quite possible that Jessica could have had a similarly dark skin tone even if Thomas' sperm was used. That's simply how heredity and skin complexion work; every Black family I know spans a hue that reflects this genetic roulette. (Think about the Cosby show and why the cast's dramatic variation in skin tone never seemed all that strange.) This isn't to say that the Andrews should not care about the mixup. Rather, it is to suggest that their expectations are strangely misguided if they think their children's African heritage can somehow be washed away.

In recent years, I've tracked a change in the publicly-stated justifications for research cloning made by advocates and scientists. The practice was originally touted as a way to make patient-specific stem cell lines in order to avoid immune system rejection. In the last two or three years, the stated reasoning has evolved to cite its potential to create disease-specific stem cell lines in order to simply study diseases. Are we now witnessing a similar shift in justifications in run-of-the-mill embryonic stem cell research?

The top story in today's San Francisco Chronicle describes new research in amyotrophic lateral sclerosis (ALS) indicates that the replacement of degenerated cells with new cells from stem cells will not address the cause of the damage to the tissue. Because it would treat a manifestation but not the root of the disease, such cellular therapy may be a dead end.

But according the article's author, headline writer ("Stem Cell Research Opens New Doors"), and presumably, the researchers, this doesn't decrease the imperative for embryonic stem cell research:

One argument for stem cell research is that it might generate fresh replacement cells for those destroyed by such horrific diseases as ALS, the paralyzing nervous system disorder popularly known as Lou Gehrig's disease.

The latest research suggests those predictions might be unrealistic: Replacing cells that die off in a disease still leaves open the question of why the cells died in the first place, which is the critical issue in any autoimmune disease, or degenerative diseases such as Alzheimer's or Parkinson's.

The findings may be the most dramatic example yet of the idea that stem cells are more valuable as a "disease model" -- used to study disease -- rather than a simple source of replacement parts....

Cell replacement therapy may never happen. But stem cell biologists insist it's hardly a failure if they ultimately achieve success along a different pathway.

We need to learn more about the mechanisms of these neurodegenerative diseases. This underscores why we're so excited about somatic cell nuclear transfer, which will allow us to make disease-specific cell lines.