Down syndrome is the most common genetic disorder, occurring in roughly one of every 700 births in the United States every year, according to the CDC.
Developmentally, individuals with Down syndrome tend to have a lower IQ and start speaking slower than other children. They also tend to exhibit these physical features:
A face with flattened appearance, especially in regards to the bridge of the nose
Eyes that slant upwards and have an almond shape, with tiny white spots on the iris
A tongue that sticks out of the mouth
Overall shorter height
Smaller hands, with a single palmar crease and pinky fingers that curve toward the thumb
Poor muscle tone
How does Down syndrome affect sleep? Many of the developmental and physical features caused by the disorder contribute to or exacerbate sleep issues in children and adults with Down syndrome, the most common of which include sleep apnea, insomnia, bedwetting, and anxiety around bedtime.
Sleep disorders and Down syndrome
According to a 2008 study, children with Down syndrome experience more nighttime awakenings, lower overall sleep time, and lower quality sleep overall, with more time in stage 1 sleep and less time in more restorative REM sleep. Children with Down syndrome also have greater resistance to and anxiety around bedtime than their peers without Down syndrome, with 66 percent falling asleep in a parent’s or sibling’s bed. Almost 20% wake up early, 40% wake at least once during the night.
Children with Down syndrome are more likely to have difficulty settling down before bedtime, and are more prone to bedwetting and dyssomnias like sleep talking, sleep bruxism, and rhythmic movement disorder than other children. Fortunately, with therapy, caregiving, and natural child development, many of these behaviors decrease in frequency or go away entirely as the child ages.
By far, sleep apnea and related insomnia are the most common sleep issues affecting individuals with Down syndrome.
Sleep apnea and Down syndrome
Sleep apnea affects between 2 to 5 percent of children. By comparison, it’s estimated that between 30 and 60 percent of children and up to 80 percent of adults with Down syndrome also have obstructive sleep apnea. One study found OSA in 31% of infants with Down syndrome.
Due to physical features caused by the condition, individuals with Down syndrome are predisposed to sleep apnea. Their upper airways are narrower, and they have larger tongues and tonsils. They also tend to have looser muscle tone and a propensity for being overweight, which is a risk factor for sleep apnea in the general population. These features combine to obstruct the airway, resulting in brief choking or gasping episodes during sleep.
Obstructive sleep apnea (OSA) is especially dangerous for individuals with Down syndrome, because the reduction in oxygen can create brain damage or worsen congenital heart defects. Besides the physical risks, sleep apnea results in sleep deprivation, poorer productivity and academic performance due to sleep deprivation, which are more concerning issues for children who already have a developmental disability.
In some cases, diagnosing OSA is more difficult in adults with Down syndrome, since it can be confused with or masked by other symptoms. One 2009 study found that 94 percent of participants with Down syndrome had OSA, with 88 percent experiencing 15 breathing pauses per hour, and 69 percent experiencing 30 breathing pauses. Overall, the adults with Down syndrome experienced more than one hour less of total sleep time than individuals without Down syndrome. There was also a high correlation between body mass index and apnea-hypopnea index (a measure of the apnea events per hour).
Because of the high propensity for OSA, the American Academy of Pediatrics recommends children with Down syndrome undergo a baseline sleep study by age 4. Individuals with moderate to severe OSA can reduce symptoms by undergoing an adenotonsillectomy, a procedure that removes both the adenoids and the tonsils.
What causes Down syndrome?
Individuals with Down syndrome are born with an extra chromosome, chromosome 21, which is why the condition is sometimes referred to as Trisomy 21. The genes in this extra chromosome cause all the features of Down syndrome.
While researchers know that the extra chromosome 21 causes Down syndrome, they still don’t know why that chromosome occurs in the first place. However, there are a few trends that may indicate a baby is more likely to have Down syndrome at birth, such as the mother’s age. Women 35 years or older are likelier to have a child with Down syndrome that younger women.
Although they present the same, there are actually three types of Down syndrome.
Affected percentage of individuals with Down syndrome
Each cell in the body contains 3 separate copies of chromosome 21, instead of the normal 2 copies
Translocation Down syndrome
Either an extra part or an entire extra chromosome 21 is present, but is attached (or translocated) to another chromosome rather than being separate, as in Trisomy 21
Mosaic Down syndrome
Some of the cells have 3 copies of chromosome 21 (as in Trisomy 21), but other cells only have the standard 2 copies
According to the CDC and the National Institutes of Health, individuals with Down syndrome may also have one or more of the following comorbid conditions of Down syndrome at birth:
Obstructive sleep apnea affects 50 to 75 percent of individuals with Down syndrome
Ear infections are present in 50 to 70 percent of individuals with Down syndrome, and 75 percent also have hearing loss
Eye diseases, cataracts, or poor vision occur in 60 percent of individuals with Down syndrome
Heart defects affect 50 percent of individuals with Down syndrome
Intestinal blockage, hip dislocation, thyroid disease, anemia and iron deficiency, leukemia, Hirschsprung disease, and blood disorders may also affect individuals with Down syndrome, to smaller degrees
Individuals with Down syndrome can have a very low birth weight, or be born with a congenital heart defect, either of which can prevent them from surviving beyond the first year. About 5% of infants with Down syndrome die within their first year, compared to less than 1% of all babies.
The risk for epilepsy of among individuals with Down syndrome increases with age, with nearly one-half of individuals over age 50 having epilepsy.
Diagnosing Down syndrome
Down syndrome is typically predicted during pregnancy via either a screening or diagnostic test. Because it’s safer and less invasive, a screening test is first used. If the screening test indicates the possible presence of Down syndrome, then a diagnostic test is performed.
Screening tests combine a blood test and an ultrasound of the baby. The blood test measures MSAFP, Triple Screen, and Quad-screen in the mother’s blood. Extra fluid behind the baby’s neck, as seen during an ultrasound, may point to a genetic issue such as Down syndrome. For women ages 35 and older, a blood test during the first trimester looks at specific pieces of the baby’s DNA that already begun to circulate in the mother’s blood.
If the screening test results (both the blood and/or the ultrasound) find something abnormal or otherwise suggest the baby may be at risk of Down syndrome, the doctors then perform a diagnostic test to further confirm the likelihood of Down syndrome. A chorionic villus sampling (CVS) diagnostic test, amniocentesis, and percutaneous umbilical blood sampling (PUBS) test examine the mother’s placentia, amniotic fluid, and umbilical cord blood, respectively, to detect chromosomal changes indicative of Down syndrome.
Treatment for Down syndrome
There is no treatment for Down syndrome, although various types of speech, occupational, and physical therapy from childhood into adulthood help individuals develop.
In part due to these therapeutic advances, as well as improved medical treatment for co-morbid conditions like heart defects, the survival rate of Down syndrome has increased dramatically over the past 50 years, from 10 to 47 years old.
It’s recommended that parents and caregivers monitor their child with Down syndrome’s sleep to observe signs of sleep-disordered breathing, bedwetting, bruxism, or another sleep disorder. Depending on the symptoms, doctors may order a polysomnography test to be performed overnight in a sleep lab to determine the scope of the individual’s sleep disorders.
Urinary incontinence is common among individuals with Down syndrome. Waterproof mattresses, mattress protectors, pillowcases, and bedding are designed to stay durable. Made from easily cleanable materials like polyurethane, these can handle regular nighttime bedwetting and won’t stain or develop an odor, as long as they are cleaned regularly.
Individuals with Down syndrome have a higher rate of obesity and of being overweight, with some studies estimating between 30 to 50% being obese. A firm to very firm mattress can do a better job supporting the weight of individuals who weigh more than 230 pounds.
White noise machines and smartphone apps
White noise machines are often used as a sleep aid for insomnia. The steady static sound of ambient noise, white noise, or nature sounds distracts from other items in the room (such as a fan or ticking clock) and soothes people into a state of relaxation conducive to falling asleep. Many smartphone apps now feature white noise libraries for insomnia with 40 or more sounds.
Depending on the extremity of an individual’s sleep apnea, the doctor may recommend the use of a continuous positive air pressure (CPAP) machine or anti-snoring device.
For severe sleep apnea, CPAP machines provide a steady flow of air during the night via a mask that fits over the sleeper’s face. For mild to moderate cases of sleep apnea, anti-snoring mouthpieces, chinstraps, pillows, and nasal plugs may be fitted between the teeth to reduce snoring and sleep-disordered breathing during the night.
Low-profile beds and padding
For individuals with Down syndrome who also have epilepsy or experience head banging during the night, the bedding environment can be made safer to prevent them from falling out and injuring themselves while they’re asleep.
Low-profile beds are usually 10 inches high at most, and sit low to the ground to prevent injury. Bed rails and bed rail pads can be attached to the side of the mattress or bed frame to keep the individual within the bed in case of a seizure or head banging episode. Bed rail pads fit over the rails so the individual doesn’t hurt themselves if they forcefully come into contact with the rails.
Sleep tips for Down syndrome
In addition to the products above, parents and caregivers may find the following tips useful in helping their loved one with Down syndrome achieve better quality sleep.
1. Establish a bedtime routine.
Perform the same activities every night 30 to 60 minutes before bedtime. Activities should be relaxing, like a bath, and signal that bedtime is near, like lowering the bedroom temperature, turning down the lights, and using a calming voice.
2. Make the bedroom cool, dark, and free of distractions.
Reserve the bedroom for sleep only. It’s important to divide activities and designate them by physical environment – the bedroom should be used for sleeping, while playtime activities can be performed in another room. Remove electronics from the bedroom.
3. Manage diet and exercise.
While it can be more challenging for individuals with Down syndrome to exercise, it can help them maintain a healthy body weight. Work with a physical therapist to understand exercise options for your child. As for diet, avoid junk foods, caffeine, and alcohol which can be stimulating and wreak havoc on sleep. Ensure your child has a sufficient dinner so they’re not hungry by the time bedtime arrives, as hunger pangs make it more difficult to fall asleep.
4. Use positive reinforcement to encourage healthy sleep habits.
Reward systems like a star chart can help reduce bedtime anxiety and create positive emotions surrounding sleep. If your child needs naptime, limit them to 30 minutes and schedule them for earlier versus later in the day so they have sufficient time to get tired again by bedtime.
The National Association for Down Syndrome is the oldest association in the country and provides resources as well as a local support group directory for parents and caregivers of children or individuals with Down syndrome.
The National Down Syndrome Congress offers resources for medical professionals, caregivers, and family members of loved ones with Down syndrome, as well as a local support group directory.
The National Down Syndrome Society is an advocacy organization that runs the Buddy Walk program and offers a toll-free hotline (800-221-4602) for parents and caregivers in need of assistance.