探索世界之基因外遗传现象 The Ghost In Your Genes 6

If inheritance was not just about DNA, if these gene switches were so important, just what could turn them on or off? Stephanie and Emend Mullins have two children, Karen and Charlotte.

When we were trying to conceive, and you see all your friends around you, getting pregnant, having children. As each month went on, you become more and more desperate.

Doctors recommended IVF treatment. In the UK alone, around 8,000 babies are conceived every year using assisted reproduction techniques, like IVF. After the third attempt, Stephanie became pregnant with Karen.

At the time, they, they didn't really highlight any risks to us. And then we went for a routine scan. And I did feel that the scan was taking an awful long time. Basically what they'd found was something called exomphalos, em, on Karen's abdomen which basically means that part of the bowel is still on the outside of the abdomen.

Doctor suspected that Karen might be suffering from Beckwith-Wiedemann syndrome, a rare condition where babies are born very large, often have oversized tongues and have a high risk of developing childhood cancers.

They couldn't say 100 percent that the baby did have Beckwith-Wiedemann syndrome. But, it was showing signs. They could see his tongue protruding on the scan. And he said the beast had very big thighs. But until Karen was actually born, we didn't know how severely affected it was going to be.

When Karen was born, it was clear he did indeed have Beckwith-Wiedemann syndrome.

Within a few hours of the birth, Karen had to have surgery to have the bowel that was on the outside of the abdomen basically put back inside repaired. Karen also had surgery to reduce the size of his tongue. And every few months, he has scans to check for tumors.

Good boy, Karen, you're a very, very good boy indeed.

Cases of Beckwith-Wiedemann syndrome caught the attention of Wolf Reik. Wolf Reik worked in developmental genetics. He was fascinated by this emerging epigenetic ghost world. He wanted to know what could throw the switches on or off. To his surprise, he found that simply placing a mouse embryo in a culture dish could trigger genes to switch off.

New Words & Phrases:

IVF: IVF is a method of helping a woman to have a baby in which an egg is removed from one of her ovaries, fertilized outside her body, and then replaced in her womb. IVF is an abbreviation for `in vitro fertilization'. 试管受精

protrude : If something protrudes from somewhere, it sticks out. 伸出,突出

thigh: Your thighs are the top parts of your legs, between your knees and your hips. 大腿

embryo: An embryo is an unborn animal or human being in the very early stages of development. 胚芽;胚胎