When you have a baby, especially if you’re in an antenatal class, or friends or family members have a child of about the same age, there is a feeling that you’re all in it together, at least at first. For me this big, life-transforming event might have felt intensely personal, but the shared connection with other new parents, who were also learning on the job, not to mention the books – Your Baby Week By Week, The Wonder Weeks – can trick you into thinking that the path is a predictable one.

From hourly feeds and wake-ups to sleeping through the night, breast- and bottle-feeding to solids, crawling to walking, maternity leave to nursery to school, the journey may have slightly different scenery, but the impression given is that ultimately it ends up in the same place.

I knew, though, from my own family experience that for some parents the path begins to deviate. For some this happens in pregnancy or at birth. For others it might be in the early weeks or months, and for others still, far later. But there’s always a moment when the parent of an ill or disabled child realises that, suddenly, they are “parenting on another plane”.

That’s what the former Guardian staffer Mina Holland calls it. Her book Lifeblood, about her daughter Vida – who, before she was six months old, was diagnosed with Diamond-Blackfan anaemia syndrome (DBAS), a rare genetic blood disorder for which there is no cure – has just been published. In it Holland tells of her

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