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Autism vs Down Syndrome

Updated: Dec 13, 2022

Autistic child is sitting on a chair and laughing


The term Autism spectrum disorder is often used to clinically define a person diagnosed with autism. This condition is due to developmental differences in the brain of the autistic person.

The child faces challenges in three major domains- social interaction, behavior, and learning skills. The symptoms are different in every individual hence the name autism spectrum disorder. It can affect individuals from all races, ethnicities, genders, and backgrounds, however, there is a genetic predisposition to autism.

Down Syndrome

Down syndrome is a genetic condition in which the person has an extra chromosome, the chromosomes are like small pockets of information that determine the development of a baby in a mother’s womb. In down syndrome the child has an extra copy of chromosome 21, hence it is also known as trisomy 21. This chromosomal abnormality leads to challenges in both the mental and physical development of the child.

What are the common signs and symptoms of autism and down syndrome?

Autism- your child may depict the signs by the age of 12 to 18 months, and some may even show signs before that, however, parents are not aware of these signs to suspect autism until their child reaches the typically speaking age.

A few signs that are indicative of autism are-

  • Doesn’t respond to their name being called.

  • Problems establishing eye contact.

  • Poor communication skills and social settings make them uncomfortable.

  • Problems using nonverbal gestures, such as pointing.

  • May have a speech delay.

  • The child has ritualistic behaviors, they get uncomfortable or aggressive if their routine changes.

  • They are good at math, science, and music.

  • Regression of developmental milestones they achieved.

Most children are often diagnosed by 3 yrs of age. However, early diagnosis and intervention can be quite helpful in the development of the autistic child, and the child can even have an independent and healthy life ahead.

Down syndrome- Down’s syndrome can affect every individual differently, some may be able to live independently, whereas few people may need help taking care of themselves. A few signs of down syndrome are-

  • Physical traits- almond-shaped eyes.

  • Flat face, especially nose.

  • Small ears.

  • The tongue may protrude out of the mouth.

  • Short height.

  • They may have a prominent crease on their palms.

  • Short height.

  • Low muscle tone, and loose joints hence they seem too flexible.

  • Mental signs- the child may have difficulty paying attention, or they may be overly obsessed with a few things.

  • Delayed attainment of milestones like crawling, walking, and talking.

  • They may take a longer time to get dressed or in doing everyday activities.

  • As the child often has mild to moderately low IQ, they may have difficulty in academics and may need extra attention.

  • It's harder for them to control their impulses, and manage their feelings, hence they can’t control their frustration.

Can autism and down syndrome be diagnosed together in a child?

Yes, about 16-18% of people with down syndrome are also diagnosed with autism spectrum disorder (ASD). As expected, the symptoms are also variable from those found in these disorders individually.

A few symptoms observed in a child with Down syndrome with Autism (DS-ASD) are-

  • The child doesn’t seem to notice if someone wants their attention.

  • Social deficits have an impact on the development of language and the use of gestures.

  • Repetitive behaviors while playing with toys, and making repetitive movements with their hands and arms, are difficult to change.

  • The sensory challenges aren’t very disruptive in down syndrome, whereas, in DS-ASD, react strongly to loud noises, hugs or cuddles, certain smells or tastes, and have difficulty in following personal grooming habits like combing, and tooth brushing.

  • The child has behavioral issues like throwing tantrums when their routine changes, impulsive behavior, and difficulty in controlling their emotions.

Therefore it is necessary to visit a specialist and get the condition diagnosed as early intervention can be quite helpful in overcoming the social, behavioral, and educational challenges in life ahead.

Screening and diagnosis of autism and down syndrome.

Autism- the diagnosis of autism is a bit of a task and based on observation as there is no medical test like a blood test to help you reach the diagnosis. The doctors look at the child's behavioral and developmental history. Diagnosing a child with autism is of utmost importance, as a delayed diagnosis can have an impact on social and personal life. Various steps in the diagnosis of autism are-

Developmental monitoring- it involves watching the kid grow and achieve milestones and encouraging conversations regarding the development of the child with the parent or caretaker.

Parents and caretakers can take part in developmental monitoring as there are several checklists available online and they can keep track of the activity of the child and talk to their doctor or a specialist if they observe delay and any domain.

Developmental screening- it is a bit more formal assessment, it involves developmental and behavioral screening at 9 months, 18 months, and 30 months. Screening questionnaires and checklists compare the development of the child to the average development of other children of the same age. If you or your doctor have doubts and if there's any predisposing factor screening can be done at times other than the recommended age.

Developmental diagnosis- if there is an area of concern a formal evaluation of the child is performed by a specialist like a development pediatrician, speech-language pathologist, or child psychologist. It involves an in-depth evaluation of the child’s development. It can highlight the child’s strengths and challenges and help you reach a diagnosis.

Down Syndrome- Two basic tests available to detect down syndrome are-

Screening test- these tests include various blood tests for detecting MS-AFP, Quad Screen, or Triple Screen, and an ultrasound. These tests help predict the chances of the occurrence of down syndrome in the baby. Sometimes even after positive results, the baby may be totally normal and sometimes the test may miss a problem that exists. These tests are comparatively safer for both mother and baby.

Diagnostic test- This test is performed after the screening test comes positive in order to confirm the results. Common diagnostic tests include-

  • Chorionic villi sampling (CVS)- examines placental materials.

  • Percutaneous umbilical blood sampling (PUBS)- as the name suggests it examines the blood from umbilical vessels.

  • Amniocentesis- examines the fluid around the baby, known as amniotic fluid

These tests look for chromosomal abnormalities to diagnose down syndrome. As it is an invasive procedure it can be a bit risky for the mother and the baby.

Autism vs Down Syndrome vs Speech delay

Although they are totally different, autism, speech delay, and down syndrome can sometimes be interlinked. Here are a few differences in these three conditions-

Social communication-

In autism, the child has difficulty in social settings, from maintaining conversation to understanding social cues.

In down syndrome, the children are often very social, and they are very talkative, they like getting attention.

Speech delay in this case the child is social and uses nonverbal communication to express themselves and follows social interests.

Intellect and learning

Autism is often associated with learning and cognitive deficits, but sometimes the child might excel in a few subjects like math, music, or science.

A child with Down Syndrome often has mild to moderately low IQ, and no mental disabilities are rare.

Speech delay affects cognitive and intellectual ability, due to difficulty in verbal communication.

It can affect the academic performance of the child as the child may have difficulty interacting with the teacher.

Nonverbal communication -

An autistic child avoids eye contact, doesn't like hugs, or cuddles and they often do not use gestures like pointing.

A child with down syndrome may develop nonverbal communication well before verbal communication.

As the child with speech delay has difficulty in communication via verbal ways, the child tries to communicate via nonverbal ways.

Physical traits-

Autism hasn't been proven to be associated with any physical deficits.

Down syndrome is often associated with physical traits: almond eyes, a flat face, or a single crease on the palm.

Speech delay hasn’t been associated with any physical deficits either.

* Speech delay can be observed in both autism as well as down syndrome, hence, timely intervention and diagnosis are very important to determine which line of treatment should be followed in which condition.

Treatment modalities available for autism and down syndrome

Autism- As autism is a developmental disorder of the brain, there are no surgeries or medicines that can reverse the condition. Various intervention techniques helpful in autism are-

  • Behavioral intervention- various techniques like ABA(applied behavioral analysis) aim at encouraging desired behavior in the child and discouraging undesired behavior. It also aims at facilitating social interaction and overcoming associated symptoms like anxiety, self-harm, and mood disorders.

  • Developmental intervention- includes the role of various specialists like-

  • Speech-language pathologist- helps the child with speech delay and learning disabilities as these are often associated with autism.

  • Occupational therapist- aim to help the child learn how to perform daily activities.

  • Sensory integration therapy- help the child to improve responses to sensory stimuli that can be overwhelming for them.

  • Educational intervention- as the name suggests, it is administered in educational settings and aims at improving the cognitive and intellectual skills of the child.

  • Medical intervention- involves the use of various drugs that can be helpful in associated symptoms of ASD like anxiety, a tendency to self-harm, hyperactivity, and inability to focus.

Down Syndrome- As down syndrome is a condition that persists lifelong, early intervention can be quite helpful physically and intellectually. Various services can be helpful for the child-

  • Speech therapy- down syndrome can lead to low facial muscle tone, a larger tongue, and frequent ear infections, it can affect the ability of children to express themselves even if they understand everything. Early intervention can be quite helpful in bridging this gap. A speech therapist helps the child with an articulation disorder, and feeding problems, and helps them learn sign language so they can better express themselves.

  • Occupational therapy helps the child learn how to crawl, walk, roll over, in day to activities, think, and problem solving.

  • As children with down syndrome have low to moderately low IQ, they often need extra help in academics.

  • Down syndrome often presents with a long list of associated health problems -

  • Hearing loss and troubled eyesight hence regular visits to an ophthalmologist and ENT specialist should be scheduled.

  • Sleep apnea is when the child stops and restarts breathing while sleeping, it can be due to a big tongue, large adenoids, or tonsils, do get the child checked up and the doctor may suggest surgical intervention if required.

  • Low immunity renders the child prone to infections.

  • Support in everyday activities, with positive affirmations like-

  • Involve them in everyday chores, and praise them when they perform tasks.

  • Give them your time and attention every day, and make sure you spend at least an hour one on one with the child.

  • Encourage them to play with other children without down syndrome.

  • As these kids do well with routine, formulate a routine, stick to it and use picture boards to help understand you better and express themselves better.

Sounderic provides online speech therapy sessions for children with various communication disorders. We would love to help you. Get in touch with us on WhatsApp at +919644466635 or schedule a consultation with us at

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