The new book Far from the Tree, by Andrew Solomon, addresses the other side of the genetics coin: How do parents cope with exceptional offspring who do not share their characteristics or their disorders with their parents?

Genetics often focuses on resemblance between family members, but Solomon writes about families in which the children differ from their parents: those families with children coping with deafness, dwarfism, Down syndrome, autism, schizophrenia, or multiple severe disabilities; or families with children who are prodigies, or who are conceived in rape, or with children who become criminals, or who are transgender. Not all children experience the loneliness of being different; some deaf children have deaf parents and some children with dwarfism have short parents (some tall children also have short parents). Many parents with exceptional offspring experience severe social isolation and stigma, but many find support from other parents. Most parents manage to love and accept their children, although this seems hardest for parents whose children have severe autism or schizophrenia and for the mothers whose children are conceived in rape. The descriptions by parents of what life with a child with autism or an adult child with schizophrenia entails are harrowing.

In 700 pages (not counting the 200 pages of notes) Solomon focuses on what it means to have a ‘horizontal’ identity: a term that he introduces to denote and include all disorders and diseases, as well as values and preferences that an offspring does not share with its parents. Solomon (1963) considers himself to be among those with a horizontal identity, as he is the homosexual son of heterosexual parents. Genetics tends to focus on clustering of traits within families, but of course genetics also predicts ‘horizontal identities’, through de novo mutations, segregation, and incomplete penetrance of genetic disorders.

One of the crucial questions in this book is to what extent parents can or should accept their children who are different, or sometimes very different. It is hard to imagine a writer other than Solomon who could be more understanding and accepting of the families he interviews and writes about. In discussing prenatal screening, cochlear implants for the deaf, or gender reassignment surgery for transgender people, Solomon's extremely well-written chapters show only empathy and compassion. At the same time, he gives succinct insights into the genetics underlying the complex traits that the book focuses on, including criminality for example. In the chapter on transgender he asks the following question: ‘Whether bodies should be altered to accommodate minds, or minds to accommodate bodies?’. The acceptance by many that bodies should be altered contrasts sharply with the case of Ashley, who is described in the chapter on disability. Ashley's parents decided to tailor her body to the child mind she would always have and decided upon growth attenuation through estrogen, removal of breast buds, and hysterectomy at age six and a half. A firestorm, which is not seen after transgender surgery, ensued.

Solomon's book is mainly based/organized around case reports in the form of lengthy interviews with patients, parents, and families, but also offers summaries of current research. For those who might feel challenged by nearly a thousand pages, there is a website, http://andrewsolomon.com/books/far-from-the-tree, with short-interview movies that offer a great taste of the book. The book itself, however, is highly recommended.