SNP Shot: Genomic Insights

Autism spectrum disorder (ASD) is a developmental condition that begins in early childhood. Its severity varies, but it is generally characterized by challenges in social interaction, difficulties with communication, and repetitive behaviors. These difficulties can affect a person's ability to function effectively in social situations, at school, and at work. Individuals with ASD also have a higher chance of experiencing mental health conditions like anxiety, depression, obsessive-compulsive disorder, and eating disorders.

From a young age, often between 1 and 2 years old, individuals with ASD may show less interest in interacting with others and may prefer objects. They often struggle with understanding and using nonverbal cues, such as eye contact, facial expressions, gestures, and body language. This makes it difficult for them to understand the emotions of others or express their own emotions appropriately. While subtle signs like reduced eye contact or social interaction might be noticeable before age 2, ASD is typically diagnosed between ages 2 and 4, when more complex social and communication skills are expected to develop.

Repetitive behaviors in ASD can include simple actions like rocking, hand-flapping, or repeating words or sounds (echolalia). Individuals may also fixate on specific topics or repeat particular thoughts; this is known as perseveration. People with ASD often prefer established routines and may become upset by unexpected changes. They may also be highly sensitive to sensory input like loud noises or bright lights.

While social and communication challenges and repetitive behaviors are core characteristics of ASD, individuals experience a wide range of intellectual and language abilities. Many individuals with ASD have mild to moderate intellectual disabilities, while others have average or above-average intelligence. Some individuals with ASD possess exceptional skills in specific areas like music, mathematics, or memory, which may be significantly higher than their overall abilities.

Some individuals with ASD may not speak at all, while others are fluent. However, even those who are fluent may experience difficulties with communication. These can include speaking in a monotone voice, using unusual vocal patterns, or choosing unusual conversation topics.

Previously, several distinct conditions were diagnosed separately, but they are now grouped under the broader diagnosis of ASD. For instance, "autistic disorder" was used to describe individuals with limited or absent verbal communication, often combined with intellectual disability. In contrast, "Asperger syndrome" was applied to individuals with average or above-average intelligence who didn't have delays in language development. The umbrella term ASD was adopted because many individuals didn't fit neatly into these specific categories, and their abilities could change over time. However, some people previously diagnosed with one of these subtypes may not meet all the criteria for the current ASD diagnosis.

Inheritance:

ASD tends to occur more often in some families, but the specific inheritance patterns are generally not well understood. Genetic changes associated with ASD typically increase a person's risk of developing the condition, rather than directly causing it. When ASD is a feature of another genetic syndrome, it can be inherited according to the inheritance pattern of that syndrome.