This morning my middle son Caleb said he missed his brother Adam who has been at respite all week. Adam goes to respite periodically because Adam is classed as disabled. He has Down syndrome and Autism, and has recently finished two and a half years of hospital-based treatment for leukemia. One could say on many levels that life with Adam is not easy and never has been. On that level respite offers our family the chance to breathe and do things that Adam can't do or doesn't enjoy. It is freedom in a certain way, but with that freedom inevitably comes the impulse to reflect on just who Adam is, and his place in our family. As his mother I too spend the week missing Adam, which may seem odd for someone who is "enjoying" a "break" from difficulty. But when Adam is away there is a piece missing from our lives, and that piece, exactly what it is and how it functions, is the key to understanding just why we need it in the first place.

When I asked Adam's brother what he missed about Adam being away, he said he "missed his partner for sleeping." The boys have always shared a room, and even from early toddlerhood Caleb has slept better when with Adam than he does alone. For Caleb, Adam's disability doesn't negate his ability to calm and offer safety to his brother, to have a strength on which he depends. That quality extends far beyond the family bounds, as many people have remarked on the strength that comes from Adam's steady nature. One explanation for this is that Adam's brain "isn't normal," which actually allows him to dwell emotionally and mentally on a different level to the rest of us and therefore to BE calmer and steadier. The shutters in Adam's head may keep out the three R's, but they also keep out jealousy, pride, greed and most significantly: fear. Adam doesn't fear the dark because he has no reason to do so, and that helps his brother. Take away his Down Syndrome and he'd be just like the rest of us, looking for the bogeyman in the corner.

What I miss about Adam is how he orients me in the real world. I know myself enough to know I'd be spinning around life pretty aimlessly if it weren't for Adam's needs that root me firmly in the here and now. He needs me, and will always need me, in ways most people grow out of through childhood. I have not always accepted this, and there were many years, mostly early on, that I begged God to let him grow up and not be so needy. I suffered a lot for Adam's disability in those years, but I want to be very clear that Adam did not need to be changed then. I did. I needed to grow to a place where I could accept my child for who he is and my place in the world for what it is.

Adam and Stephanie

I might have said yes in those days, if you had asked me would I want Adam to be cured. And I would have missed all the amazing moments of seeing him develop and knowing the difficulty he overcame each time. The first steps that took 27 months to take. The first signs and rudimentary words that are still emerging ten years on. The ability to relate to others in socially acceptable ways that many people have worked together to bring out. I would have missed the clouds lifting from his vision, the jokes he's played that have had us rolling on the floor in stitches. If you cure him, you make him just like anyone else, and now I see that that would have destroyed who Adam is and what our family is because of him. His brother and sister know difficulty and patience because of Adam, they know Makaton signs and Mr Tumble, they know what disability is, they know "special kids" and peace because of Adam. They are who they are in part because of their brother, and if you cure Adam you change us all permanently.

The question is what exactly do we want to cure and why? Not Down syndrome really, but maybe the difficulties it brings to our collective life. But surely we're not afraid of difficulty or nobody would go to college, or own an iPhone, or get married. So maybe the difference that comes with being disabled, but if we were afraid of difference we would all wear the same black suit every day of the week. We'd all eat the same food, speak the same language and shop at the same stores so that we wouldn't stand out. We say we don't want people to suffer, but again that's pretty ridiculous if you think about body piercing, or getting tattoos, or athletes training for their sports, or any number of ways we make our own selves suffer for our own pleasure.

Maybe that's it: we want to cure Down syndrome because it's not self-imposed, and we chafe as humans against anything we didn't decide or do for or to ourselves. We want to cure disability because it's not the right kind of difference, or difficulty, or suffering. If you ever walked around town with my Adam you would realise very quickly that he is like a magnet for people to stare at, even more than some freakish outfit or massive tattoo or Jessica Ennis's physically supreme body. I get stared at when I'm with him, and on one level I hate it. But on another level that's also what I miss when he's not with me. I miss not being ordinary, I miss people not being bewildered by the "abnormal" child I fight for, I miss people not seeing that difficulty and difference and suffering can certainly come in pretty cool little packages, EVEN if we didn't choose it ourselves.

Adam came to us and he changed our lives for the better. Would I cure his Down syndrome? Probably not. Would I rather try to cure the tendency in all people to be selfish, and unloving, and unwilling to accept life for what it is and not look for self-gratification at every turn? Now that's a silly question.

Stephanie Brock lives in Scotland, and is a mother to three lovely children and married to Brian Brock, a theologian at the University of Aberdeen. In her professional life she has worked as a teacher, a nurse, a researcher, and currently a children and family consultant to the Scottish Episcopal church of Aberdeen. Her journey with Adam has led her to be involved with many organisations including the Sitter Service of Aberdeen, local children's charities, and Welcoming Church Forum, a group that seeks to interface between families of children with special needs and churches in Aberdeen. She (sometimes!) keeps a blog at www.aberdeenbrocks.blogspot.co.uk.