“The genes we inherit from our parents are packaged inside structures called chromosomes. We all have twenty-three pairs of chromosomes. Each chromosome pair consists of one that came from Mom and the other from Dad. Our genes are arranged along the chromosomes like beads on a string.”
He draws these strings and beads on the board. They look like necklaces.
“You can think of genes as recipes. They’re the body’s instructions for making proteins and everything about you from eye color to disease susceptibility. The letters and words that make up the gene recipes are called DNA. Instead of the A-B-C alphabet, the DNA alphabet letters are A, T, C, G.”
He circles these letters on the board.
“The change underlying Huntington’s involves these DNA letters. The Huntington’s gene is located on chromosome
four.”
He points to a dot on one of the necklaces.
“There is a sequence, C-A-G, that repeats over and over in the HD gene. On average, people have seventeen CAG repeats in the HD gene. With Huntington’s, there are thirty-six or more CAG repeats. This expansion of the gene is like changing the recipe, and the altered recipe causes the disease. You with me so far?”
She nods. She thinks so.
“So let’s look at your family tree. Remember, we inherit two copies of every gene, one from our mother and one from our father. Your dad inherited a normal copy of the HD gene from his father, but he inherited an expanded copy from his mother, who had HD. Huntington’s is what’s called a dominant disease. You only need one copy of the altered gene to inherit the disease.”
He draws a square next to a circle on the board and draws a line between them. He writes grandfather over the square and grandmother over the circle and draws a line between them. He then shades in the circle black with the marker. He draws a line like a stem down from her grandparents to a shaded square labeled father and connects her dad’s square to an unshaded circle labeled mother.
“Now there’s your generation.” He draws squares for JJ and Patrick, circles for Meghan and Katie. He blackens JJ’s square, and the sight of it blackens Katie’s stomach. She shifts her focus to her circle, empty for now. She closes her eyes for a moment, a white circle emblazoned in her mind’s eye, holding on to it. A symbol of hope.
“Each of you inherited a normal copy of the gene from your mom. Remember, your dad has one normal copy of the HD gene from his father and one expanded copy from his mother. So each of you inherited either his normal copy or the expanded copy. If you inherited the normal copy from your dad, you will not get HD. If you inherited the expanded copy, you will develop HD if you live long enough.”
“So that’s how each of us has a fifty percent chance of getting this.”
“Exactly,” he says, smiling, seemingly pleased that she followed his biology lecture.
So it really does comes down to random chance. Shit luck. Nothing she has done or will ever do can affect it. She can eat a vegan diet, practice yoga every day, have protected sex, stay away from drugs, take her vitamins, and sleep eight hours a night. She can pray, hope, write positive affirmations on her bedroom walls, and light candles. She can meditate on an empty, white circle. None of it matters. There it is on the board. She either already has the gene or she doesn’t.
“Fuck,” she says. Her eyes widen and she presses her lips together, her mother’s voice in her head scolding her with a harsh Language! “Sorry.”
“That’s okay. You can say ‘fuck’ in here. You can say anything in here.”
Her lips part and she exhales. She feels that she has to be so careful now, especially around her family, worrying about what not to say, what not to notice. Sunday suppers in that cramped kitchen are particularly excruciating, where every spoken and withheld word seems to stomp on a minefield of eggs, crushing them into sharp shards that slice her lungs, making it painful to breathe.
There’s a noticeable pause in conversation. The air in
the room fills with something. An invitation. A promise. A dare.
“When I was a kid and we played truth or dare, I always picked dare,” says Katie.
“So you were a risk taker.”
“No, not at all. It was just the better choice, better than having to admit some embarrassing truth about myself.”
“What was so embarrassing about you?”
“I dunno normal stuff.”
The baby of the family, she was forever trying to keep up with her older siblings. JJ, Patrick, and Meghan knew about sex, drinking, pot, everything before she did, and her ignorance made her feel stupid. And it was particularly difficult following Meghan. Katie spent most of her childhood faking what she knew, hiding what she didn’t.
“This feels a little like truth or dare,” she says.
Truth: Find out whether she is going to get Huntington’s disease or not.
Dare: Live without knowing, wondering every other second whether she already has it.
She never liked that game. She still doesn’t want to play it. Eric nods, seemingly impressed and contemplative, as if this comparison had never occurred to him before.
“Tell me,” he says. “What would it mean to find out you’re gene negative?”
“Uh, that would be amazing. Biggest relief ever.”
Duh.
“How do you think it would affect your relationship with JJ?”
Oh. The lightness from her imagined, obvious relief drops into an unliftable weight in her lap.
“And what if his baby has it?”
“He’s not finding out.”
“In eighteen years, his kid can get tested. What if your niece or nephew is positive? How will that be for you?”
“Not good,” she says, lowering her head.
“What if Meghan and Patrick are positive, and you’re negative?”
“Jesus,” she says, leaning forward to knock three times on Eric’s desk. “Why are you painting the worst possible picture?”
“You said being negative would be the biggest relief ever. See how it’s not that simple?”
“Yeah, I see it.”
Thanks a fuckin’ lot.
“What would testing positive feel like?”
“Rainbows and kittens.”
“How would you handle it?”
“I wouldn’t jump off the Tobin, if that’s what you’re getting at.”
This is getting too intense. She squirms in her seat. Eric notices. Fuck this. This isn’t mandatory. She can get up and leave anytime she wants. She doesn’t have to be polite to Eric. She doesn’t have to care what he thinks. She doesn’t have to see Eric ever again.
“So, what would you do? Would anything in your life change?” he asks.
“I dunno. Maybe.”
“You in a relationship?”
She shifts to the edge of her seat and eyes the door.
“Yeah.”