If you are a parent of a child with Down syndrome, you may be surprised to learn your child could possibly have autism as well. Studies suggest there is a link between autism spectrum disorder (ASD or autism) occurring alongside Down syndrome. The methodology for diagnosing autism in individuals with complex medical disorders can vary depending on the condition.

For parents, a dual diagnosis of autism with Down syndrome adds a layer of complexity. In this post, we will explore signs that may point to a dual diagnosis, as well as tips to help you navigate a dual diagnosis.

What is Down syndrome?

Down syndrome (also known as trisomy 21) is a naturally occurring genetic disorder wherein a child is born with an extra copy of chromosome 21. There are two other forms of Down syndrome: mosaic Down syndrome and translocation Down syndrome, but trisomy 21 makes up 95% of all cases. Researchers estimate about 5,000 babies are born with Down syndrome in the United States each year. The cause of Down syndrome is currently unknown; however, the age of the mother may play a part in its frequency.

Down syndrome causes certain genes on chromosome 21 to be over-expressed, which can showcase in a variety of ways. Some common physical features of individuals with Down syndrome include:

  • Short stature
  • Low muscle tone
  • Flat bridge of the nose
  • Extra space between the first and second toes
  • Extra fold of skin around the eyes
  • Widely spaced and upward-slanting eyes
  • Enlarged tongue
  • Brushfield spots in the iris of the eye
  • Wide hands with short fingers
  • Small head, ears and mouth

In cases of Down syndrome, developmental delays often occur and mild to moderate cognitive impairment is common. Developmental traits of Down syndrome may include:

  • Delayed milestones such as the ability to crawl, walk and talk
  • Slower learning
  • Short attention span
  • Impulsive behavior
  • Memory impairments
  • Higher prevalence of cooccurring conditions

The life expectancy of individuals with Down syndrome is around 60 years depending on the severity of health problems that may develop. Some children with Down syndrome are completely healthy while others may be born with or later develop severe health problems. Common health concerns of individuals with Down syndrome can include:

  • Overweight or obese
  • Weakened immune system
  • Heart defects
  • Vision and hearing impairment
  • Thyroid problems
  • Respiratory issues
  • Sleep disorders
  • Mental health issues
  • Gastrointestinal and digestive issues
  • Dental problems
  • Childhood leukemia
  • Early-onset Alzheimer’s and dementia

Source: Down Syndrome Resource Foundation

What is autism?

Autism is a complex neurodevelopment disorder that affects one’s social interaction, communication and behavior. The DSM-5 requires the presence of persistent deficits in social communication and interaction across multiple contexts, and restricted and repetitive patterns of behavior in order to receive an autism diagnosis. These deficits also must significantly impair social functioning and cannot be better explained by a different intellectual disability or developmental delay.

Individuals with autism may have difficulty having two-way conversations and shared interests with others. They may also be rigid with their routines and present repetitive behaviors. Generally regarded as a spectrum of severity, autism will present differently in everyone.

Receiving a dual diagnosis

While Down syndrome is diagnosed through a blood test and can be detected during pregnancy, autism is a subjective diagnosis based on observations. The research on dual diagnosis is limited. Due to its complexity, children with Down syndrome are likely to receive a delayed diagnosis for autism in comparison to children who do not have Down syndrome. In addition, researchers believe the prevalence of autism in children with Down syndrome is even higher than 16%, but the diagnosis is missed due to behaviors being misattributed to Down syndrome rather than autism.

If your child has Down syndrome and you are wondering if they also may have autism, you can look to common signs and symptoms of autism.

  • Difficulty or disinterest in social interaction and communication
  • Repetitive behaviors often with intense focus (stimming)
  • Significant challenges with expressive language (language expressing needs and wants)
  • Increased or decreased sensitivity to stimulation including sounds, textures and touch; indifference to pain is also common
  • Difficulty with change or transition (adherence to routine)

Children with a dual diagnosis of Down syndrome and autism have a distinct learning profile from children with only one of either diagnosis. This means a child with a dual diagnosis has distinct strengths and weaknesses that differ from those with only one of either diagnosis when it comes to learning. Children with a dual diagnosis often use less symbolic communication symbols and may process language in chunks rather than voicing out each individual word. In general, children with a dual diagnosis gesture more frequently, are more likely to imitate or repeat others, and display less variety in facial expressions.

What you can expect

Autism is a common and manageable condition that can be diagnosed with a formal evaluation. With early diagnosis and intervention, you and your child can learn to effectively manage their behavior. Your child may receive care from a psychiatrist or other developmental-behavioral physician specializing in autism. Medications can also help manage your child’s autism symptoms and behaviors.

Maxim Healthcare Services provides quality care in home- and community-based environments. Our clinical team uses a flexible, empathy-based approach with our ABA therapy tailored to the needs of your child. If you need support navigating your child’s autism spectrum disorder diagnosis, we are here to help! Contact your local Maxim office for more information.