Autism spectrum disorder (ASD) is a neurological disorder that affects social interaction, communication, and behavior. It is estimated that 1 in 150 children in Singapore have ASD, with boys more likely to be affected than girls. Common signs include difficulties with social skills, communication, repetitive behaviors, and sensitivity to change in routines. While ASD affects each person differently, early diagnosis and treatment such as behavior therapy and speech therapy can help children with ASD develop skills and live independently. Parents should trust their instincts if they suspect ASD and seek help from professionals.