Mutants – Armand Marie Leroi

An unusual combination of historical accounts of people with physical anomalies and the modern genetics and molecular biology that help explain the anomalies. Obviously originally published in Britain and not re-edited for the American audience, it still has British spellings and phrasings that occasionally cause the reader to stumble, but also sometimes add charm.

It starts off a little slow – I thought it was going to be all historical accounts, and I wasn’t up for that. But it quickly turns fascinating. For instance, there is a condition called Kartagener’s syndrome characterized by impaired sense of smell, male infertility, and reversal of all the internal organs – the heart is on the right of the chest rather than the left. These symptoms all result from defective cilia on the surfaces of cells. People with defective cilia can’t move mucous out of their lungs and sinuses properly, leading to chronic sinusitis and bronchitis, leading to impaired sense of smell. Sperm use cilia to move, so if the cilia are defective, the sperm are immotile and the man is infertile. And, early in embryonic development, a set of cilia set up a standard pattern of beating right-to-left, creating a gradient in a signaling molecule that the body uses to determine right from left. With no cilia, there is no gradient, and the embryo randomly chooses which side is right or left for the development of internal organs. So actually half of people with Kartagener’s syndrome have a normal arrangement of organs, even though they have no cilia.

Leroi is an engaging writer, with an interesting whimsical style. About the X and Y chromosomes, he says: “[They] are physically ill-matched: the first is large, the second small. The remind one of those apparently odd couples – a large matronly woman and a small dapper man – that one sometimes finds among professionals of the Argentinian tango.”

You may not want to read it if you’re pregnant. Or you’re trying to get pregnant. Or you have a two-year-old who likes to find and discuss the pictures in your books. Also, the cover has images of people with genetic anomalies, which meant I only read the book at night after the kids were in bed.

Mutants: On Genetic Variety and the Human Body
Armand Marie Leroi
2003

Available from Amazon