I read someplace that scientists made a mouse with two moms and no dad. Does this mean that two women can have children now?

-A curious adult from California

May 27, 2004

No, two women can't have a baby without a sperm donor. Let's look at why it worked for these mice but wouldn't work for people.

In most animals, babies are made from sperm from the father and an egg from the mother. The sperm and egg each give half of the chromosomes or DNA to the embryo. (The mother's egg also gives the rest of cellular machinery the embryo needs to develop into a baby so making a baby with two fathers is definitely NOT possible!)

Where can you find out if you have a cancer gene that goes through your family? All my family seems to be getting cancer and it doesn't seem to leave anyone out.

-A curious adult from the United Kingdom

May 26, 2004

You have a very good question, and a great place to start would be to contact a genetic counselor. Where do you find a genetic counselor? Check with your primary or OB/GYN doctor who can refer you to one of these specialists. Alternatively, you can check for a local genetic counselor at the website of the National Society of Genetic Counselors (see link below). It is important to have the support and expertise of a genetic counselor through this process.

I read someplace that scientists made a mouse with two moms and no dad. Does this mean that two women can have children now?

No, two women can't have a baby without a sperm donor. Let's look at why it worked for these mice but wouldn't work for people.

In most animals, babies are made from sperm from the father and an egg from the mother. The sperm and egg each give half of the chromosomes or DNA to the embryo. (The mother's egg also gives the rest of cellular machinery the embryo needs to develop into a baby – so making a baby with two father is definitely NOT possible!)

Besides the father, is there anyone who could take a paternity test? Maybe his brother or sister?

-A curious adult from British Columbia, Canada

May 25, 2004

The short answer is that it is possible to determine paternity without the father. You are right that the way it is done without the father is to use other relatives. Aunts, uncles, cousins, siblings and grandparents can all be used.

Everyone, except identical twins, has a unique set of DNA. DNA is made up of 4 bases or letters, A, C, G, and T. These 4 letters form the written code that makes up the DNA sequence.

In Down syndrome besides regular trisomy there is a chance of having a translocation of chromosome no.21 with chromosomes 13, 14,or 15. One of the parents can be a balanced carrier of this translocation. I read that if a father is carrier then there

May 25, 2004

Good question. I knew about translocation mutations and Down syndrome but hadn't looked into it in too much detail before.

People usually have two copies of each chromosome (except for the sex chromosomes, X and Y). About 95% of Down syndrome cases are caused by having three copies of chromosome 21, as shown in the image to the right.

A balanced carrier is someone who has the right amount of chromosome 21 but one of the pairs is stuck to another chromosome (see the image to the right). These people still have 2 copies of chromosome 21 and so don't have any Down syndrome symptoms. However, they can give their kids Down syndrome.

I saw some DNA beauty products on sale at different department stores. Are they effective? Should they really cost so much? Please advise.

-A curious adult from California

May 18, 2008

Beauty products that use DNA -- is this just a bunch of snake oil or is it for real? That depends on which DNA makeup you're talking about.

It looks to me like there are two kinds of DNA based cosmetics. The first uses DNA research to come up with new kinds of ingredients to add to cosmetics while the second promises to use your genetic profile to create a makeup just for you.

Is there a possibility of using stem cells from a relative\'s umbilical cord to use for spinal cord cell cure treatment? I saved my niece\'s umbilical cord last year hoping there would be a day to use for a cure for my spinal cord injury or if my n

-A curious adult from Arizona

November 10, 2006

One day this sort of thing might be possible. In fact, there is even a claim that this very strategy has worked in South Korea.

A woman who had been a paraplegic for 19 years received matched umbilical cord stem cells. According to the scientists who did the work, within six weeks she could walk with a walker.

But after a second operation her condition worsened. And now she complains of severe pain.

Let's start with the most controversial experiments -- those using embryonic stem cells. Embryonic stem cells are said to hold the most promise because they can become any other kind of cell.

So why isn't everyone using embryonic stem cells? Because their use has major ethical and medical issues.

Right now an embryo needs to be destroyed to get a hold of its stem cells. Anyone who considers the embryo to be a life is going to be troubled by this.

Early animal work suggests that adult stem cells might be an alternative to embryonic stem cells. People are finding nerve-like cells in umbilical cord stem cells. They are also finding that when these cells are put into the spinal cord environment, they can turn into nerve stem cells.

Studies using both nose and umbilical cord stem cells have shown that the cells went to the injury and turned into some nerve cells. A number of studies showed some improvement and some did not. The early safety data looks promising as well.

Is there a genetic reason some people survived the plague during the middle ages?

-A curious adult from California

May 12, 2004

There may be. There are many stories where someone who was in constant contact with plague victims didn't die. Maybe genetics is the explanation.

For example, in 1665, the plague hit a small village in England called Eyam. The town quarantined itself to keep the Black Death from spreading into the rest of the country. A year later, the plague had burnt itself out but half of the townspeople were dead. Was there something special about the half that lived?

So, does CCR5-delta 32 protect people from the plague bacteria? Probably not. Mice infected with the plague bacteria died at around the same rates whether or not they had the CCR5-delta 32 mutation.

Why then is this mutation so common in Europeans and even more common in people whose ancestors came from Eyam?

Maybe smallpox is the reason. Smallpox killed 3 in 10 infected people for thousands of years in Europe. Recent studies suggest that smallpox, like HIV, can't infect someone with the CCR5-delta 32 mutation.

Can white parents have a black baby? Even if the grandparents are white too?

May 11, 2004

Tough question to answer but here's my best shot. It certainly seems possible for two white people to have a black baby even if the baby's grandparents appear white as well. Even though the genetics behind all of this are really poorly understood, there are lots of stories where white parents have black babies. In fact, one such story may become a movie (see the link below).

Can you tell someone\'s age by a DNA test?

April 29, 2004

The short answer is that at this time we can't exactly figure out how old someone is from their DNA. However, it is fun to think about how this might be done in the future by looking at how DNA changes with age.

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