Autism spectrum disorders (ASD) are a set of heterogeneous disorders, more diagnosed in men than in women, with the majority of cases of unknown etiology. Why it occurs to a lesser extent in women than in men is also unknown. In this sense, there are several etiological models that are being investigated, such as Protective Female Effect, greater male genetic variability, The Male Extreme Brain Theory or Neuroendocrine hypothesis. What does seem to be happening is an underdiagnosis in women in the absence of intellectual disability, due to specific characteristics of the female phenotype.