The genetic basis of autism goes under the microscope in this special Easter edition of Naked Genetics, from Kat Arney. One per cent of UK children have autism, a complex range of disorders that can be challenging to understand and live with. But recent advances in genetics are shedding new light on the origins of the condition. Plus, we look at the genes underlying Specific Language Impairment, find out why cancer has the X factor, and meet a hopeless-sounding gene of the month.