“I want to be tall like you but without the stoop please,” my daughter said. “Or that nose bump. Or those varicose veins! But… otherwise… how do you not look 50 when you are?”

I knew that was an afterthought of a compliment. No stranger to the Gene Blame Game, I was used to teen angst heaping a pile of perceived faults at my door. Better sense prevails now, but a while ago I was deemed responsible for everything from period pain and zits to poor posture and bad dentition.

“Stop quibbling about small superficialities!” I snapped at her. I wasn’t ready to tell her yet, but weighing me down miserably was something far from small or superficial. It was, and will always remain, plain terrifying.

I’d felt no telltale lump, no cautionary sign. Out of nowhere, a cankerous growth the size of a shirt button had shown up as a shadow in my annual mammogram. For nine days – the longest in my 52 years – I waited for the biopsy report. Never a smoker, very regular with exercise, careful to eat healthy, I was certain the growth would be benign. When it was declared otherwise, I could only think of my smiling 18-year-old daughter.

I was reading the biopsy results as I watched her pull on a cheery curve-hugging red T-shirt, in a rush to catch a first college lecture in time. But I only saw grey and thought: “This must never happen to her.” Even as the surgery was being planned, all I could think of was whether this discovery meant my daughter would need to be screened at an age earlier than when my gynaecologist first told me to get a mammogram.

Mulling over the implications of “bad” heredity is one of the most painful tasks for parents, from slow learning issues and attention disorders to sicknesses with strong familial links, like cardiovascular disease and cancer. The latter are particularly difficult to come to terms with, altogether more personal, more condemning to accept they have happened. You can try to raise your children well, set an example of how to manage that streak of hotheadedness, get tutors to help them learn at their slower pace, feed them healthy food, shower them with love – and it takes one dot of defective DNA to take you on a guilt trip thinking you’re the worst parent ever. It makes telling them harder. At 18, my daughter learned years ago I was not a Supermom, but to admit a flaw in myself that might affect her so profoundly was almost, if not quite, as scary as the lump itself.

We live in a joint family and are an over-communicative bunch. So the children tend to pick upon all kinds of anxieties even when we try to keep them simmering below the surface. Things you’d prefer left unsaid for a bit are out before you anticipate. Because I tried too hard to buzz calmly through those awful nine days before the biopsy results, my daughter knew I felt anything but calm.

“Tell me what you’re really thinking,” she blurted at breakfast one morning, not long after.

I looked at her. I saw the ridged nose she had inherited from me, the bad teeth and the scoliosis. We had spent long years trying to help her straighten the last two in ways that would do the least damage to her self-esteem. One set of braces was inevitable, but she had revolted against a second. “One set of braces in my mouth is all I’m going to wear and I can’t possibly play football with another right on top of me,” she declared. So we saw her through intensive rounds of physiotherapy, yoga, swimming and Pilates under a range of trainers. She now stands straighter-backed and taller as a result. But there was nothing I could do to help her deal with a hereditary predisposition to breast cancer. Nothing except show her how to face it and cope.

Laying down the marmalade knife, I told her that although I should only feel sheer relief at the lesion being excised and the treatment calling for no more than two Tamoxifen tablets daily for five years, rather than any ravaging chemo or radiation cycles, I was still sad and upset by this brush with cancer. It was a gnawing, niggling feeling. “No family should have to face this,” I said. My daughter, pragmatic teen that she is, pointed out that would only be possible in a dream world. But her face clouded as she added that a couple of her friends’ mums were undergoing chemotherapy after mastectomies had them lose a breast.

More discussions later, she acts as if she’s reassured. But she has started asking, “Sure it couldn’t be melanoma?” each time her usually beautiful skin erupts with some irritation. While her older brother begs her to “read up on that before playing Drama Queen,” I find myself uttering the same words my mother used to tell me. “Let those genes do their worst,” I say. “You’ll fight them when you have to.”

If she inherits that message, along with anything else, perhaps all will be well.