Health: That's my son she's talking about: When Ann Lee read an article on the Health page, alarm bells rang in her mind. One year on, she tells how her family has adjusted to a painful diagnosis

A year ago this week I read an article on the health page that changed my life. I'm a journalist myself, and know that an article about a rare illness can provoke usually unwarranted certainty in some readers that they have the ailment, so I treated my instant shock of recognition with some scepticism.

The article was written by a woman called Carol Taylor. It described how she had discovered by amniocentesis that her unborn son had a sex-linked chromosomal disorder known as Klinefelter's syndrome. The condition, one of the most common genetic defects after Down's, is found only in boys and can cause both physical and mental abnormalities: behavioural and learning difficulties, infertility, development of breasts at puberty and, because the growth hormones are disturbed, unusual tallness.

I pushed my fears to the back of my mind and went to work as usual. When I got home my husband's first words to me were: 'There's an article in the Independent I want you to read.'

The article provided the last piece of the jigsaw that we needed to understand our son Oliver. He is our second son, our middle child. He had had a difficult birth but otherwise his development had been completely normal. Yet we always felt that all was not quite right with him. His speech was late, he was emotionally immature and seemed unusually vulnerable: he cried easily and was frightened of things that most children took in their stride, such as dealing with even the mildest playground aggression. He also had difficulties with spelling and verbal comprehension.

Teachers and doctors were sympathetic but obviously thought I was being both fussy and pushy. His older brother and younger sister are both very bright, outgoing children. 'Don't compare them,' was the advice I received.

When the Independent article appeared Ollie was 10, looked 12 and behaved like an eight year old. He was also overweight and got teased at school for being fat. In addition, it seemed to us that his genitals were very small.

The symptoms Carol Taylor described in her article fitted Ollie like a glove: tallness, timidity, poor verbal achievement, small genitals. Not only did she set out the cause of Klinefelter's syndrome but she identified the main UK expert on it, Dr Shirley Ratcliffe at Great Ormond Street Hospital for Sick Children, London.

The day after the article appeared I went to my office party; I stayed for an hour or so, drank mineral water and retreated to my office to write a long, coherent letter to Dr Ratcliffe about Ollie. I then tore the letter up, returned to the party and got very drunk very fast.

The next day, when the hangover retreated, I rang my GP. I saw him on Christmas Eve and spelt out my worries; he was open, sympathetic and while telling me that I was almost certainly wrong about Ollie, said that of course I must be reassured.

I took Ollie to see Dr Ratcliffe in early February. A blood test was taken for chromosome analysis but Dr Ratcliffe was so sure of the diagnosis that she told me immediately he was a Klinefelter's boy. I think the hardest moment was when she took me through the measurements and said that his head was one SD (standard deviation) below the norm. I asked why and I was told that his brain was smaller than the norm.

I was far more devastated by the diagnosis than I had ever anticipated and walked out of Great Ormond Street in a daze. On the way home we went shopping in Sainsbury's; the first person I met was my old health visitor, who cried cheerfully, 'My, Ollie, haven't you got tall]' - only to have me burst into tears among the vegetables. The blood test duly confirmed the diagnosis.

I took about six months to come to terms with the knowledge that my child is physically and mentally different. The feeling of loss is just as intense as it would have been had the discovery been made when Ollie was a small baby. He may go on to higher education, but I would be fooling myself if I expected him to achieve in the way I once hoped he would. His adolescence will be punctuated by tests and hormone treatments. For now he accepts that he 'grows too fast', but before long he will have to be told that he is different from other boys. When he is older he will know that he will never have children.

I look at my little boy now with such a fierce desire to protect, with such love with such sadness for the glimpses I get of the sort of child Ollie might have been. I see it in the fine bones of my other children, in their litheness and agility and their bright, quick ability.

The whole process has been made more difficult by the secrecy involved in our discovery. The firm medical advice is not to tell anyone, as these children cope best if they are left to get on with it and are subject to the same expectations as everyone else. In addition, any sexual difference in our society is still so taboo that to expose Ollie to gossip, jokes or speculation is the last thing I would want. But I so long to be able to explain to friends and relations that we've gone through this experience and that Ollie has these problems to cope with now and in the future.

Ten months after the diagnosis of Klinefelter's I feel more reconciled to it. Oliver now attends a small private school that is co-ed (we felt this was an important factor), has good academic standards and a very confidence-building atmosphere. He has been there a term and, although it has been a difficult transition, he is responding well to the demands made of him.

I know that I'm in some ways one of the lucky ones. Despite Ollie's verbal difficulties, he has an above-average intelligence: some Klinefelter's boys get degrees. And as we are both small, his final height will be little more than 6ft. The non-assertiveness that is a feature of Klinefelter's contributes to a kind and gentle nature which makes him popular with other children. And we have discovered his condition at the time when hormone treatment will have the best effects. We are able to help him emotionally, physically and intellectually to make the most of what he has.

Maybe some other parents will read this article and look at their sons as I looked at mine a year ago and wonder. Maybe a woman who is contemplating a termination of a Klinefelter's foetus will read this and know that her child will be able to lead a happy life despite his handicap - 66 per cent of Klinefelter's boys diagnosed before birth are aborted. Maybe a doctor will read this and look more carefully at that tall toddler whose mother is fretting about delayed speech. However, I am still not brave enough or ready to put my own name to this article and, like Carol Taylor a year ago, I write it under a pseudonym.