In most cases, ASD is diagnosed between 15 and 30 months. Some children exhibit typical early development, only to lose acquired language and social skills between 15 and 30 months. These cases qualify as regressive autism. However, there are instances of late onset autism where individuals appear to develop typically until adolescence or even adulthood before displaying symptoms consistent with autism. In such cases, an identifiable neurological insult, such as, e.g, herpes