We are going to talk about a genetic disorder that hits close to home for our family. A friend’s young child was recently diagnosed with 1p36 micro deletion syndrome. It’s the most common of the rare genetic disorders, however, there is still much unknown about it. Needless to say, they are very concerned, so this week, we researched this disorder to see what they are facing. Grab a cup of coffee and let’s go over the results…you may know a child who has this but hasn’t been diagnosed.
I’ve never heard of this before. What is it?
According to Unique, (unless otherwise noted, the information included in this article came from Unique) 1p36 deletion syndrome is a chromosome disorder. A chromosome disorder is a change in chromosome number or structure that results in a set of features or symptoms. People with 1p36 deletion syndrome have lost a small but variable amount of genetic material from one of their 46 chromosomes.
Chromosome 1 is the largest chromosome and represents about eight percent of the total DNA in cells. Base pairs are the chemicals in DNA that form the ends of the ‘rungs’ of its ladder-like structure. For healthy development, chromosomes should contain just the right amount of material – not too much and not too little. People with 1p36 deletion syndrome have one intact chromosome 1, but the other is missing a tiny piece that affects their learning and physical development in relatively predictable ways.
When was this deletion discovered?
Not too terribly long ago, is the answer to that question. It was described for the first time in the late ’90s, but the first case was published in ’81.
While considered rare, (one in 5,000 newborn babies will be diagnosed with it), it is still one of the most
commonly observed chromosome deletion disorders.
What are some common symptoms?
While not all children will have all of these features, they have been found to be the most common. According to the Unique study:
Developmental delay. All children studied so far have shown some degree of learning disability, usually in the moderate to severe range. These children will need support with learning. The amount of support needed by each child will vary, although most benefit from attending a special school.
Many parents report that the most effective learning strategies include music, lights, visual learning, and books, especially tactile ones. Patience, repetition, and lots of praise, and encouragement are important. Some children have found a touch screen computer a useful learning aid. Some children learn to draw simple lines and shapes, read and write. Parents note that many children have good memories, particularly of faces and places.
Delayed or absent speech has been reported in 98 percent of children. From around 3 years of age, some master a signing system, although this can prove difficult for children experiencing prolonged Hypotonia (poor muscle tone).
Some children use a few words, and a minority of children may develop some complex speech. Speech and language therapy has helped some children enormously. It’s important to remember that they understand far more than they are able to express!
Hypotonia (floppiness/poor muscle tone), especially in babies, but may persist indefinitely. Standing and walking are skills that children with 1p36 deletion syndrome find especially challenging, often despite years of practice and training in standing frames and walkers and using ankle/foot orthotics.
But there is a great range in the age at which children start to walk – from one year, 5 months to eight years, with an average of three years and 10 months. Children often continue to need help climbing stairs, getting in and out of bed, and the bath. Once mobile, some children go on to run, climb, dance, and even ski. However, walking may not prove possible for all. A small number do not master sitting unaided and require the use of special supportive seating. The floppiness (low muscle tone or hypotonia) that is one cause of this severe motor delay is usually obvious from birth, affects nine out of 10 babies, and gradually improves with age and physiotherapy. A number of families also reported a lack of balance in their children.
Feeding difficulties. Feeding problems are common in newborn babies. Two-thirds of babies in one study either sucked too weakly to meet their nutritional needs or had difficulties coordinating sucking with swallowing. Swallowing studies have shown dysfunction in almost three-quarters of babies and swallowing difficulties and choking mean that both breast or bottle feeds can take a long time.
Seizures. Seizures affect around half to three-quarters of all children. The onset of seizures ranged
in the Unique survey from birth to 3 years (the medical literature cites seizures starting from 4 days of age to 7 years). Some families report just one or two seizures in babies that never recur. For most children, the seizures are relatively well controlled with medication. There are some children, however, for whom their epilepsy is extremely difficult to control, despite multiple medications. In two of the Unique families, the seizures evolved into Lennox-Gastaut syndrome, an uncommon form of epilepsy that is difficult to treat.
Cardiomyopathy (disease of the heart muscle) and minor heart defects. Studies suggest that heart (cardiac) problems occur in around 44 percent of children. Approximately 30 percent of the heart problems were cardiomyopathy, where the heart is enlarged and doesn’t pump as strongly as it should, and around 70 percent had structural defects. Cardiomyopathy may require medication but may also gradually improve over time.
Hearing loss. Hearing loss affects around two-thirds of people with 1p36 deletion syndrome. It can vary from mild loss at various frequencies to severe loss at all frequencies. There is evidence that the loss is progressive in some children, so an annual hearing check is recommended.
Vision defects. Vision problems are very common and variable. Around 80 percent of children have been found to have some vision defect. The problems can be due to the structure and function of the eyes, or problems with the brain processing the information received from the eyes. In the Unique survey, the most common problem affecting the eye itself was strabismus (squint), affecting around half of the children. Other eye problems that have been found include optic disc atrophy, short or long-sightedness, nystagmus, photosensitivity (photophobia), cataracts, and astigmatism.
A large soft spot (fontanelle) at birth that is slow to close.
Thyroid. Studies have indicated that around one child in five has been found to have a low thyroid hormone level (hypothyroidism) and to need thyroxine replacement and it is suggested that all children should be monitored for thyroid function.
Infections: Two-thirds of Unique’s children with a 1p36 deletion suffer from recurrent infections whose range and nature suggest some degree of immune compromise. Fourteen children have had repeated pneumonia and four contracted meningitis. Chest infections, colds, and gastroenteritis are all common, often longer-lasting than in typically developing children. However, many families report that as children get older (over the age of 4 or 5 years) they are no longer as susceptible to infections and are in good general health.
Behavior: In general, children with a 1p36 deletion are placid and affectionate. However, they are as
vulnerable to frustration as other children with communication difficulty, and temper tantrums and aggression can present carers with challenges. Behavioral problems have been reported in as many as 50 percent of children and the evidence from Unique seems to back up this figure.
So what caused this deletion to occur?
Both parents of a child with a 1p36 deletion should have their own chromosomes tested, although 90 – 95 percent will have normal chromosomes. The chromosome break is then said to have occurred out of the blue (de novo). In the remaining families, one parent usually has a balanced rearrangement of their own chromosomes which has become unbalanced when eggs or sperm were created. In both situations, there is nothing you can do to stop this, just as there are no environmental, dietary, or lifestyle factors known to cause it.
So there is nothing that either parent did before or during pregnancy that caused the deletion to occur and equally nothing could have been done to prevent it. In our friend’s case, their first child was not affected, but their second one was.
What are the prognosis and life expectancy?
MedicineNet states, “Part of the prognosis for individuals with 1p36 deletion syndrome really depends on how much DNA is missing from the p36 region. Children with the most amount of DNA missing have the worst prognosis (poor, with severe symptoms). However, even these individuals may have some responses to treatments. Consequently, some individuals may have a relatively good prognosis (a loving relationship with understanding and patient caregivers and family members) to a poor prognosis and early death from significant physical problems. While 1p36 deletion syndrome is so new that data on projected lifespan is lacking, there are reports in the medical literature that some patients reach adulthood“.
Treatments! What’s available?
“Treatment is limited; symptomatic treatment is the usual treatment available. The heart, eye, muscle tone, and swallowing problems may be reduced by specialists in those fields. The earlier the diagnosis and treatment, the more likely these problems will become manageable or minimized. Some clinicians report good results with behavior modification training. Some affected individuals do well and can participate in many social events“.
Our friend speaks out…
Our friend reflects on her son’s diagnosis, “Even though it was the scariest day of my life, I am grateful for the event (a seizure-like episode) that led Zayn to go to the hospital. Because he was experiencing similarities to a seizure disorder, we were able to get the referral for genetic testing. I have to wonder how many kiddos like my son, who are just a little behind on milestones and have some gastrointestinal issues but haven’t had any serious episodes, may have this syndrome but don’t know it? I wish genetic testing was offered through insurance at zero to very little cost for anyone pregnant or already having children. It shouldn’t take a major event to finally get a referral so insurance will cover it.
“There has been a whirlwind of emotions that have come with this diagnosis. But the strongest emotion has been one of relief. Now that we know what he has, we can start getting him all the tests and therapies to help him be as independent as possible“.
Maybe the researcher reading this will take up the cause!
If you are reading this, and you are or know of, a researcher looking for a great cause, this is it! We don’t know enough about this disorder to effectively help these families. Are you the one? Will you be the researcher who finds a way to remedy this defect? Maybe you are reading this and you would like to fund research for this disorder! Do it! These children deserve to have adults advocating for their lives.
Lastly, if you read this article and feel that your child has this disorder, go strong. Tell your doctor that you want them tested. The more you know, the earlier you know, the better the outcome. Don’t wait.
That’s all I have for you this time, dear readers. If this syndrome hasn’t hit your family, be thankful, and if you have children, educate them so that when they see a child struggling, they will understand why. Empower your children so that they may be good humans and not unintentionally hurt a child or that child’s sibling as they maneuver through life.
We shall meet here again next time, to share another cup of coffee. Until then, be good to yourself and each other.