Types of Autism Spectrum Disorder (ASD)

Autism is a spectrum, meaning it varies widely in symptoms and severity. While the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, 5th Edition) now groups all types under “Autism Spectrum Disorder,” there are still subtypes or profiles that many professionals and families refer to:

1. Classic Autism (Kanner’s Syndrome)

• Features: Significant challenges in communication, social interaction, and repetitive behaviors. 
• Often includes: Delayed language development, intellectual disability. 
• Signs: Avoids eye contact, doesn’t respond to name, struggles with routines and transitions. 

2. Asperger’s Syndrome

• Features: Milder symptoms, especially in language and cognitive development. 
• Often includes: High intelligence, deep interest in specific topics, social awkwardness. 
• Note: Officially part of ASD now, but still commonly used. 

3. Pervasive Developmental Disorder – Not Otherwise Specified (PDD-NOS)

• Features: Symptoms don’t fully meet criteria for other subtypes but still significant. 
• Also known as: “Atypical autism” 
• Signs: Milder social and communication challenges. 

4. Childhood Disintegrative Disorder (CDD)

• Features: Normal development for first 2–4 years, followed by severe regression. 
• Rare: Often involves sudden loss of motor, social, and language skills. 

5. Rett Syndrome

• Note: Once considered a form of autism, now known to be a genetic disorder caused by a mutation in the MECP2 gene. 
• Primarily affects: Girls 
• Features: Loss of purposeful hand use, motor issues, seizures, and developmental delays. 

🔍 Causes of Autism Spectrum Disorder

ASD doesn’t have a single known cause — it’s thought to be the result of a combination of genetic and environmental factors.

🧬 1. Genetic Factors

• Many genes are linked to ASD, often affecting brain development or neuron function. 
• ASD can run in families, though specific genes may vary. 
• Some cases involve rare genetic mutations, including: 
  • Fragile X syndrome 
  • Rett syndrome 
  • Tuberous sclerosis 

🌍 2. Environmental Factors

These don’t cause autism directly but may increase the risk in genetically predisposed individuals:

• Parental age (older mothers/fathers) 
• Pregnancy or birth complications: 
  • Low birth weight 
  • Premature birth 
  • Oxygen deprivation at birth 
• Prenatal exposure to: 
  • Air pollution 
  • Certain medications (e.g., valproic acid, thalidomide) 
  • Viral infections during pregnancy 

🧠 3. Brain Development Differences

• Imaging shows differences in brain structure and connectivity. 
• Abnormalities in early brain growth, particularly in regions responsible for: 
  • Social behavior 
  • Communication 
  • Sensory processing 

❌ What Doesn’t Cause Autism

Despite myths, research confirms:

• Vaccines do NOT cause autism (extensive studies have debunked this). 
• Bad parenting is not a cause (early theories like the “refrigerator mother” idea are outdated and harmful).

✨ Let’s Grow Together!

At Amazing Growth, we provide educational content, parenting tips, and awareness materials designed to support holistic child development. Visit our website or YouTube channel for more.

• 🌐 Website: https://amazinggrowth.net 
• 📺 YouTube: https://www.youtube.com/@AmazingGrowth 
• 📧 Email: info@amazinggrowth.net 

⚠️ Disclaimer

This article is intended for informational purposes only. It does not replace professional medical or psychological advice. If you suspect a child may be showing signs of autism, please consult a qualified pediatrician, developmental specialist, or licensed therapist for accurate assessment and guidance.

Article by: By Miss Antoinette – Amazing Growth

About the Author

Miss Antoinette Hunter is a licensed and certified educator with a strong academic background in early childhood education and special needs instruction. She holds a P-3 teaching certificate, a Master’s in Teaching, a Bachelor’s degree in Sociology with a concentration in Family Health and Youth Services, and an Associate’s degree in Early Childhood Education. Currently serving as a Developmental Intervention Specialist (DI), Antoinette is passionate about helping children thrive by empowering parents, caregivers, and professionals with effective, faith-guided strategies to support growth and development.