What is the 1q21 microdeletion syndrome?
The 1q21 microdeletion syndrome is a syndrome in which children have a developmental delay combined with one or more congenital defects due to missing a piece of the hereditary material of chromosome 1.

What is 1q21 microdeletion syndrome also called?
Children with this syndrome are missing a piece of chromosome 1. Missing a piece of hereditary material is called a deletion. A chromosome consists of a short arm and a long arm. The short arm is called p, the long arm q. In children with the 1q21 micro deletion syndrome, part of the long arm (q-section) of chromosome 1 is missing. Hence the addition of the letter q after the number 1. The numbers 21 after the q indicate which part of q-section of chromosome 1 is missing, namely the part that has been given the number 21. The word micro indicates that a small piece of the q part of chromosome 1 is missing. A syndrome is a combination of features and problems that have a similar cause.

Monosomy 1q21
Another name used is monosomy 1q21. The word monosomy indicates that there are not two chromosomes present as usual, but that only one chromosome is present. In the case of 1q21 micro-deletion syndrome, not all of chromosome 1 is missing, but only the 1q21 part.

How common is 1q21 micro-deletion syndrome?
The 1q21 micro-deletion syndrome is a rare disorder. It is not known exactly how often 1q21 micro-deletion syndrome occurs in children.It is estimated that this condition occurs in approximately one in 2000 children. It is likely that some of the children have never been diagnosed with this condition because it has never been studied.
Several hundred children with this syndrome are known worldwide.



In whom does 1q21 micro-deletion syndrome occur?
The 1q21 micro-deletion syndrome is present before birth. Usually it becomes clear during the first or second year of life that the development of children with this syndrome is different from that of other children without this syndrome.
Both boys and girls can have the 1q21 micro-deletion syndrome.

What is the cause of the 1q21 micro-deletion syndrome?
Error in the hereditary material
The 1q21 micro-deletion syndrome occurs because a piece of chromosome 1 is missing. To be even more precise, the piece called 1q21 micro is missing. Sometimes numbers are put after the number 21 to indicate that an even smaller piece of chromosome 1q21 is missing, for example 1q21.1 or 1q21.2.

Originating in the child itself
In a large percentage of children, the error in the genetic material causing a piece of chromosome 1 to be missing occurred in the child itself during the fusion of the egg cell and sperm cell. This is also called de novo, which means originated in the child itself. The parents themselves do not have this error in the genetic material of their body cells.

Inherited from a parent
In a small proportion of children, the child has inherited the error from one of the parents. Sometimes this parent was already known to also have had problems with learning and/or delayed development, but the diagnosis was not yet known because earlier the tests to make this diagnosis did not exist.

Incomplete penetrance
Not every person who is missing the piece of 1q21 on chromosome 1 actually develops symptoms as a result of having this piece of hereditary material missing. Some people never develop symptoms during their lifetime. This is also called incomplete penetrance.



Information on chromosome 1q21 micro
On chromosome 1q21 micro, information is stored in genes that describe how parts of the body should be built and should work. Because children with the 1q21 micro deletion syndrome lack this information, their bodies are built differently than usual. This causes the problems associated with 1q21 micro deletion syndrome. In addition to chromosome 1, each child has 22 other chromosomes, and this information is available during the construction of the body. There will therefore still be a lot of good construction.

What are the symptoms of 1q21 micro deletion syndrome?
Variation
There is a great variation in the amount and severity of symptoms that different children with 1q21 micro-deletion syndrome have. It is not possible to predict in advance which symptoms a child will have. No child will have all the symptoms listed below at the same time. This also depends on the size of the piece of the chromosome 1q21 micro that is missing, in one child this is a larger piece than in another child. Children who are missing a larger piece of hereditary material often have more problems than children who are missing a smaller piece of material, but this is not necessarily always the case. This means that the characteristics listed below can occur, but do not have to occur.

Pregnancy and childbirth
Usually there are no special features during pregnancy or childbirth.

Low muscle tone
Children with 1q21 micro deletion syndrome are more likely to have lower muscle tone. This makes them feel weaker than other children. When children are lifted, they must be properly supported. Because of the lower muscle tone, the joints of the elbows and knees, for example, can be easily overstretched. This is called hypermobility.

Problems with drinking
Some babies have problems drinking. They do not grasp the breast or bottle properly and let go easily. Feeding babies with this syndrome often takes more time. Because of these feeding problems, children may remain light in weight. This is called failure to thrive.

Developmental delay
Children with 1q21 microdeletion syndrome may develop more slowly than their peers. This is not the case for all children with 1q21 microdeletion syndrome. The degree of developmental delay can range from none to moderately severe. Children with developmental delays start rolling, sitting, standing and walking later than their peers. Most children eventually learn all of this, but at a later age than children without this syndrome. Children with this syndrome often move somewhat lumbering and less smoothly than children without this syndrome.
Often children with this syndrome have problems with fine motor skills, such as writing, drawing or cutting. This is more difficult for them than for their peers. This is called dyspraxia.



Problems with talking
Learning to talk, also occurs at a somewhat slower pace than in children without this syndrome. Most children are able to learn to talk in sentences with several words. Children often have difficulty with sentence structure. Often children find it difficult to tell how they are feeling or to tell what they have experienced in a day in an understandable order.
Children with this syndrome also often have lower muscle tone in the face, which makes them pronounce words and sentences less clearly and sometimes harder for strangers to understand. This is called dysarthria.
Understanding language spoken by other people is often better for children with this syndrome than speaking it themselves.

Learning at school
Some of the children with this syndrome have problems learning. In some of the children, the IQ is lower than 70, the limit below which is spoken of as an intellectual disability.

AD(H)D
AD(H)D is more common in children with this syndrome. Children with ADHD have difficulty sustaining attention for a longer period of time when performing a task. They play only briefly with a certain toy and then move on to another toy. Children are easily distracted by a noise or movement in the room. At school, children have difficulty keeping their attention on schoolwork for longer periods of time.
Children may have difficulty sitting still and prefer to move around all day. Children tend to do first and only then think about whether it is wise, this is called impulsive behavior.

Autistiform characteristics
Children with a 1q21 microdeletion syndrome are more likely to have autistiform features. Children are more introverted and do not have much need for contact with other people. They live in a world of their own. Making eye contact is often difficult for children.
Children with autistiform traits often like a fixed predictable structure in the day. They find it difficult when this is deviated from. Unexpected events are also difficult. Children can get very angry or very sad when unexpected events occur, because they do not know how to deal with this. Children with autism often find it difficult to understand the emotions of other people and do not know how to respond. Playing together and having fun is often difficult for children with autism.
Also, children often have a preference for certain toys or a certain hobby that they can enjoy for a long time.

Anxiety
Children with this syndrome are more likely to suffer from anxiety. For example, fear of being alone without the parents, fear of the dark or fear of unknown and strange situations.

Epilepsy
One to three out of ten children with 1q21 micro deletion syndrome will experience epileptic seizures. Different types of epileptic seizures can occur. This is closely related to the age at which the child develops epilepsy. Common seizures are seizures with stiffening (called tonic seizures), seizures with repeated jerks (called clonic seizures), seizures with small jerks in different parts of the body (called myoclonia) or seizures with staring (called focal seizures with reduced consciousness). Also, febrile convulsions are more common in children with this syndrome.

Problems with sleep
Sleep problems are common in children with this syndrome. Some children have difficulty falling asleep. Some of the children wake up frequently during the night and then have difficulty getting back to sleep. Also, children are often awake early in the morning.
In some of the children, the sleep problems are caused by epilepsy during the night.

Physical characteristics
With many syndromes, children often have changed physical appearance. This does not bother children themselves, but it can help doctors recognize that there is a syndrome and possibly which one. Also, this often makes children with the same syndrome look more alike than their own siblings, even though the children are not related.
Children with 1q21 micro-deletion syndrome often have a smaller head circumference. The forehead may be higher and wider than usual. The eyes, nose and mouth are often close together. The eyes are often a little deeper in the head, making the eyes appear small. The tip of the nose is often firm.

Hands and feet
The thumbs of the hands and the big toes of the feet may be wider than usual. A small proportion of children have more toes than usual.

Smaller head circumference
A large proportion of children with this condition have a smaller head circumference. A head circumference that is too small is also called microcephaly.



Height
Some of the children are smaller than their peers; others are of normal height.

Vision problems
Some of the children are nearsighted or farsighted and need glasses to see well. Squinting is more common in children with this syndrome. As a result of squinting, there is an increased risk of developing a lazy eye. Also, a special form of squint, Duane syndrome is more common in children with this syndrome. Some children have cataracts; the lens of the eye is not clear but cloudy, causing children to see blurry. Cataract is also called cataract. It also occurs

Problems with hearing
Half of the children have problems hearing because they suffer from fluid behind the eardrum. This can cause sounds to be heard less loudly.

Teeth
Some of the children have fewer teeth than usual. The teeth may be different in shape.

Problems with chewing
Children with this syndrome are more likely to have a problem chewing. Children prefer soft food that they do not have to chew or food that is cut into small pieces. Chewing takes children a long time. Tough meat is difficult to grind for children with this disorder, so children prefer to spit it out rather than swallow it.

Schisis
A small percentage of children have a cleft in their lip or palate. This is called a schisis. This cleft can be very small and unremarkable. Sometimes all that can be seen is that the uvula is made up of two parts instead of one part. A schisis can also cause problems with drinking and eating.

Reflux
Children with 1q21 micro deletion syndrome are more likely to experience reflux of food from the stomach into the esophagus. This is called (gastroesophageal) reflux. Because the stomach contents are acidic, the acid thus also enters the esophagus, sometimes even the mouth. This acid can cause pain, making children cry and sometimes not want to eat. It can also make children spit up.
The acid can make the esophagus irritated and inflamed. If this is not discovered and treated in a timely manner, it can cause spitting up with blood strings in it.

Drooling
Children with this syndrome easily suffer from drooling. This is due to weakness of the muscles in the face and around the mouth, which causes saliva to run out of the mouth easily. This is because this is the easiest route for the saliva, the other option of swallowing saliva takes conscious attention from the child until swallowing saliva is automated.

Congenital heart defect
A proportion of children with 1q21 micro deletion syndrome have a congenital heart defect. This often involves a hole between the two atria or both chambers of the heart. This is also called atrial septum defect (ASD) or ventricular septum defect (VSD). Transposition of the great vessels, truncus arteriosus or tetralogy of Fallot can also occur. The aortic valve may consist of two rather than three blades. Sometimes there is a narrowing in the large body artery (a coartcataio aortae).
Children will not be affected by a mild heart defect, but they will be affected by a more severe heart defect. This can cause symptoms such as rapid fatigue, sweating when eating or drinking, or a blue discoloration during exercise.





Constipation of the bowels
Constipation of the bowels is common in children with this syndrome. The stool then does not come every day and is often hard, causing children to have difficulty defecating. This can cause abdominal pain and a bulging belly. It can also cause loss of appetite.

Congenital abnormalities of the kidneys
In some children, urine flows from the bladder back to the ureter and sometimes to the kidneys. This can cause the kidneys to contain too much fluid. This is called vesico-urethral reflux and hydronephrosis. Children are usually not affected by this themselves. However, it can make children more susceptible to a urinary tract infection.

Cleanliness
Most children with this syndrome become potty trained at a later age than usual.

Groin or umbilical hernia
A portion of children with this syndrome have an inguinal or umbilical hernia.
This can be seen and felt as a lump in the groin or next to the navel. Often children are not bothered by this, sometimes the inguinal or umbilical hernia causes pain.

Hypermobility
Children with this syndrome have low muscle tone. Because of the lower muscle tone, the joints of the elbows and knees, for example, can be easily overstretched. This is called hypermobility. Many children have flat feet due to the lower muscle tone.

More susceptible to infections
Children with 1q21 micro deletion syndrome are more susceptible to getting infections at a young age. Respiratory infections or ear infections occur regularly.

How is 1q21 micro deletion syndrome diagnosed?
Story and examination
Based on the story of a child with a developmental delay and some striking external features, a syndrome may be suspected. However, there are many different syndromes that can all cause these symptoms. Often additional testing will be necessary to make the diagnosis of 1q21 micro-deletion syndrome.

Blood tests
Routine blood tests in children with 1q21 micro-deletion syndrome do not find any abnormalities that point to the diagnosis.

Genetic testing
The diagnosis of 1q21 microdeletion syndrome is often discovered when all chromosomes are examined at the same time, this is called Array testing. During this examination, it is noticed that a piece of chromosome 1 is missing. Other forms of genetic testing, which are often performed nowadays (whole exome sequencing), can also reveal the presence of 1q21 micro deletion syndrome by means of a special CNV analysis.

MRI scan
Children with developmental disabilities will often undergo an MRI scan to see if there are any brain abnormalities. Often no abnormalities can be seen on this MRI scan. Sometimes the brain cavities are somewhat larger than usual. This abnormality is not specific to 1q21 micro deletion syndrome and is also seen in other syndromes.

Metabolic testing
Children with developmental delay often receive metabolic testing of blood and urine to see if there is a metabolic disease that is explanatory for the developmental delay. No abnormalities are seen in children with 1q21 micro-deletion syndrome.

EEG
Children with epilepsy often get an EEG to see what type of epilepsy is involved. The EEG often shows epileptiform abnormalities. These abnormalities are not characteristic of the 1q21 micro deletion syndrome, but can also be seen in many other epilepsy syndromes.

Ophthalmologist
Children with 1q21 micro syndrome are always seen once by an ophthalmologist to check for problems with vision.



ENT specialist
Children with 1q21 micro-deletion syndrome are always seen once by an ENT doctor to see if there are any problems with hearing. Or if there are any indications of a schisis.

Pediatric Cardiologist
Children with this syndrome are always seen once by the pediatric cardiologist to see if there is a congenital heart defect. The pediatric cardiologist can look at this through an ECHO of the heart.



ECHO abdomen
An ECHO examination of the abdomen can be used to look for evidence of a congenital abnormality of the kidneys.

How is 1q21 microdeletion syndrome treated?
No cure
There is no treatment that can cure 1q21 microdeletion syndrome. Treatment is aimed at ensuring that the development of children with 1q21 microdeletion syndrome proceeds as smoothly as possible and that additional problems are detected as early as possible and treated where possible.

Pediatrician
In the Netherlands, care for children with rare syndromes is often coordinated by the pediatrician in the child's own home. In addition, children can also be supervised by a special pediatrician who specializes in the care of children with congenital and often rare disorders. This paediatrician is called paediatrician EAA: paediatrician for hereditary and congenital disorders. EAA pediatricians are working in an increasing number of hospitals in the Netherlands. The EAA pediatrician consults with the child's own pediatrician in the child's home region to determine the best way to care for the child. The EAA pediatrician can also ask specialized pediatricians for help, such as a pediatric cardiologist for heart problems, a pediatric pulmonologist for lung problems, a pediatric MDL doctor or pediatric surgeon for intestinal problems, a pediatric nephrologist or pediatric neurologist for kidney and/or urinary problems, a pediatric neurologist for children with epilepsy or movement disorders, a pediatric orthopedist for children with bone abnormalities.

Physical Therapy
A physiotherapist can give parents tips and advice on how to stimulate their child as best as possible to ensure optimal development. Exercises to improve balance can help to reduce problems with balance.

Speech therapy
A speech therapist can give tips and advice if there are problems with sucking, drinking, chewing or swallowing. Some children benefit from a special teat (special needs teat) which makes drinking from the bottle easier. Mothers can pump breast milk so that children can still receive breast milk as nutrition through the bottle.
The speech therapist can also help stimulate speech development as best as possible.
Talking can also be supported by means of gestures or pictograms. In this way children can learn to express themselves even when they cannot use words yet.

Dietician
When children are not growing enough, a dietician can look at how energy-enriched foods can still ensure adequate growth.

Tube feeding
Many children with this syndrome have difficulty drinking formula from the breast or from the bottle. It is therefore often necessary to feed children through a tube, so that they can get enough food to grow. The tube goes through the nose and throat to the stomach. When a tube is needed for a longer period of time, a small operation can be performed to insert a tube through the abdominal wall directly into the stomach. Such a probe is called a PEG probe.Later it can be replaced by a so-called mickeybutton.
There are different types of ready-made tube feeding that can be given through the tube.
Some parents choose to give finely pureed food through the tube. This is called a blended diet.

Occupational Therapy
An occupational therapist can give tips and advice on how to make a child's care and daily activities as smooth as possible. The occupational therapist can also give advice on materials that can stimulate a child's development.

Rehabilitation Physician
A rehabilitation doctor coordinates the different therapies and also advises on aids such as an adapted baby carriage, a wheelchair, splints, orthotics or adapted shoes.
It is also possible to go to an adapted toddler group through a rehabilitation center and receive therapy there as well.

School
Most children with 1q21 micro-deletion syndrome need additional guidance in learning. Some of the children can follow regular education with the help of support. Another part of the children eventually goes to special education in cluster 3 or 4 because there they are in smaller classes and can get more help and also therapy.



Orthopedist
An orthopedist can offer advice on how parents can help their children cope with frustration, anger and tantrums. Providing ways to communicate other than talking (pictures, gestures, speech computer) can help reduce frustration. Children can also learn to express their emotions through play or drawing.

Child and adolescent psychiatrist
A child and adolescent psychiatrist can give advice on how to deal with behavioral problems such as ADHD or autism. Sometimes it is necessary to give behavior-regulating medication such as methylphenidate for ADHD or risperidone or aripiprazole for sensitivity to stimuli in the context of autism. For each child, the potential benefits of using these medications must be weighed against their drawbacks.

Seizure treatment epilepsy
Most epileptic seizures go away on their own within a few minutes. Bystanders then do not need to do anything to stop the seizure. It is important to remain as calm as possible and to leave the child alone as much as possible.
If a seizure has not stopped after 3-5 minutes, it will often be advised to give medication to stop a seizure. The treating physician will always indicate what time of day is best for a particular child. Medications that can be used to stop an attack are diazepam rectiole (Stesolid®), midazolam nasal spray, midazolam rectiole, lorazepam or clonazepam drops.
The effect of these medications occurs after a few minutes. Afterwards, the child will usually fall asleep, sometimes not.

Treatment epilepsy
With the help of medication we try to prevent the epileptic seizures as much as possible and preferably to ensure that there are no more epileptic seizures. Sometimes this can be achieved quite easily with one medication, but in a proportion of children it is not so simple and combinations of medications are needed to make the epileptic seizures occur as much as possible or not at all.
Different types of medications can be used to control the epilepsy. There is no clear preferred medication. Medications that are often used are sodium valproate (Depakine ®), levetiracetam (Keppra ®), clobazam (Frisium ®) and zonisamide (Zonegran ®).

In a portion of children, medication will not succeed in controlling the epileptic seizures. There are also other treatments that can have a good effect on the epilepsy, such as a ketogenic diet, a vagus nerve stimulator, or treatment with methylprednisolone. A combination of these treatments with medications that suppress epilepsy is also quite possible.

Treatment of sleep problems
A fixed sleep ritual and pattern can help children sleep better. The drug melatonin can help to fall asleep better. There are also forms of delayed-release melatonin that can also help children fall back asleep when they wake during the night. Sleep aids should not be given to children because they become accustomed to them and cannot live without them. Sometimes the drug alimemazine is used to help children sleep better. It is always important to rule out epilepsy as the cause of sleep problems, in case of epilepsy treatment is needed.

Vision problems
Some children need glasses to see well. When children squint, it may be necessary to tape one eye for several hours a day to prevent children from developing a lazy eye. When squinting is severe, surgery may be necessary to straighten the eyes more. When the lens of the eye is very cloudy, surgery may be necessary to replace the lens of the eye with an artificial lens.

ENT doctor
Children with frequent middle ear infections may require tubes to prevent new middle ear infections.
A hearing aid may be helpful, when children hear worse


Schisis team
Children with a schisis are often seen and treated by a schisis team. This team often includes several doctors, nurses, and other support people who look at the best way to treat the schisis. One or more surgeries may be necessary.

Dentist
Children with 1q21 microdeletion syndrome are often given extra check-ups by a special dentist who specializes in the dental care of developmentally disabled children because it often requires special approaches and extra time. The dentist looks at whether fluoride treatment is needed to prevent cavities in the teeth. Some children require braces to ensure that the teeth are straightened in the jaw. A dental hygienist can give advice on how to best practice oral hygiene.

Reflux
Reflux can also cause children to eat poorly. By thickening the food with carob gum, the food can flow less easily back from the stomach to the esophagus. There are also medications that can make the stomach contents less acidic so that the esophagus is less irritated when the stomach contents flow back. Medications used for this purpose are ranitidine, omeprazole or esomeprazole. If all of this is not enough, surgery may be necessary in which the transition from the esophagus to the stomach is made narrower, which also makes it harder for food to flow back. This is called a Nissen operation.

Drooling
Drooling can be reduced by making children aware of the need to swallow their saliva. Exercises that involve practicing closing the mouth can also help.
There are medications that can reduce drooling. The most commonly used medication for this is glycopyrrhonium. Sometimes treatment of the salivary glands by means of botox or surgery may be necessary to make children drool less. For each child, the pros and cons of each treatment will need to be weighed.

Pediatric Cardiologist
The pediatric cardiologist assesses whether treatment of a congenital heart defect is necessary or if only monitoring is needed. Sometimes medications are needed to support the heart. Antibiotics may also be needed in certain situations. A severe heart defect may require surgery. These operations are performed by the thoracic surgeon.

Blockage of the intestines
The drug macrogol can help keep stools flexible and soft and encourages the intestinal wall to stay active. This allows children to pass their stool more easily. Furthermore, it remains important to ensure that children get enough fluids and fiber, and exercise as much as possible. Sometimes suppositories are needed to get the stool going.

Cleanliness
Potty training can begin when the child can sit on a potty by itself and begins to show interest in the potty. Often this is at a later age than usual in children with this syndrome. Tips that can help with potty training can be found in the potty training folder.

Pediatricurologist
Through surgery, the pediatric urologist can stop the flow of urine from the bladder to the ureter. There are several techniques that can help.

Antibiotics
A portion of children who have frequent recurrent infections benefit from low-dose antibiotics to prevent new infections. For each child, the benefits of giving the antibiotics must be weighed against their drawbacks (antibiotics also kill beneficial bacteria in the intestines).





Financial side of caring for a child with a disability
Caring for a child with a disability often involves additional costs. There are various laws that provide compensation for the care of children with a disability.
In addition, there are schemes that parents can use to get compensation for these extra costs. You can find more information about this in the leaflet finances of a child with a disability. You can find more information about this in the leaflet finances for a child with a disability.

What can you do as a parent to optimize your child's development?
Remember that when you play, frolic, dance, sing, chat, laugh and/or read books with your child, these are all ways in which your child trains his or her brain to make steps forward in development. So it is not the case that only moments of therapy are moments of training, which is what many parents think. It is also good to alternate exercise with relaxation, this is necessary to allow the learned to be stored in the brain. Training all day long without any moments of rest is counterproductive.
In addition, it is invaluable to let your child feel that you love them, that they are loved and may develop at a pace that suits them. This is especially important for children who develop differently from the "norm." "Being good as you are and being supported by people who love you is, very important for a child's development. Especially the parents and the other children in the family who are close to the child are very important to give the child this feeling. It is good that parents realize the value of this for the child and what role they have in this.
It is also important to think about what feels good for you as a family and for you as a parent and what gives you energy. Make sure that there is conscious space for moments that give this good feeling. Finally, it is important that you as parents also take good care of yourself, caring for a child who develops differently asks even more of parents than caring for a child who develops without problems. It is good to take care of yourself or have someone take care of you, so that you as a parent also have the energy to continue to guide your child in a way that suits you. Realize that parenting includes learning to let go. Many parents find this difficult, especially when their child develops differently from other children. But it can still be necessary to let go of part of the care at certain moments, even if the other person does things differently than you. Your child learns from these differences and it gives you the opportunity to rest yourself or to get new energy.

What can you do as a family to deal with having a disorder in a family member?
As a family of a child where there is a disorder, it is good to make sure you are empowered. It is good to realize what thinking, emotional, inner and physical strengths you have as a family and how you can use these to take good care of each member of the family. See what suits you as a family. See what you can do (or not do) to use this strength in the best possible way. And remember that each member of the family has different qualities with which you can complement and strengthen each other.

Guidance
A social worker or psychologist can provide guidance on how having this disorder can find a place in daily life. It often takes time for parents to come to terms with the fact that the future expectations of their child look different than they might have expected. Also, many parents find it difficult to divide their time and attention between the child with the disability and other children in the family. In the brochure Attention and time for brushes, you will find tips that can help you with this.

What is the prognosis of 1q21 microdeletion syndrome?
Persistent problems.
Children who have developmental delays due to 1q21 microdeletion syndrome often continue to have these problems into adulthood. Some of the young people can live independently. For things like finances, however, they may need help and support. Another part of the adults needs more help and support in daily life and goes into assisted living.

Autoimmune disorders
A small proportion of adults with 1q21 microdeletion syndrome appear to be more susceptible to developing an autoimmune disorder such as Sjogren's disease, rheumatoid arthritis or multiple sclerosis.

Mood disorders
Adults with 1q21microdeletion syndrome appear to be more susceptible to developing a gloomy mood or depression.

Pyschosis
A proportion of adults with this syndrome develop psychosis during adolescence or young adulthood. A psychosis is a state of confusion where young people may see images or hear sounds that are not actually there. This can leave young people very confused and anxious.

Life expectancy
There are no known data on the life expectancy of children and adults with the 1q21 micro deletion. Life expectancy is probably not much different than for children and adults without this syndrome. Life expectancy may be shortened by a difficult-to-treat form of epilepsy and/or a severe congenital heart defect.

Transition of care
Between the ages of 16 and 18, care is often transferred from child specialists to specialists who provide care to adults. It is important to think about this in a timely manner. Is there a need to transfer care to adult specialists or can the primary care physician provide the care that is needed.And if there is a need to transfer care to adult specialists, to which physician(s) will the care be transferred? In which hospital can the care best be delivered. The process of transferring care is called transition. It is important to think about this early and make a plan for it together with the doctors involved in pediatric care.
Also, when a young person reaches the age of 18, a lot of things change. For more information about these changes we refer you to the article changes in care 18 +.

AVG
An AVG is a doctor who specializes in the care of people with intellectual disabilities. The AVG focuses on the prevention, treatment and limitation of physical and psychological problems that are related to an intellectual or physical disability. To this end, the AVG works together with the family doctor, medical specialist, behaviorist and/or other therapists (such as a physiotherapist or speech therapist). There are an increasing number of outpatient clinics in the Netherlands where AVG work and where children and adults with a mental disability can go with their questions about their disability. In addition, AVG also work in institutions and are involved in specialized children's day care centers. A list of outpatient clinics can be found on the website of the NVAVG (Dutch Association of Physicians for the Mentally Handicapped).

Children receive
Adults with the 1q21 micro deletion syndrome can have children; there is no known relationship between having this syndrome and fertility. These children have a 50% chance of developing the 1q21 micro deletion syndrome themselves. It is not possible to predict to what extent children will be affected by this disorder. This may be to the same extent, to a lesser extent or to a more severe extent. If the adult does not want to or cannot have children, it may be necessary to consider contraception, about which you will find more information in this leaflet.



Do siblings also have an increased risk of also getting 1q21 microdeletion syndrome?
The 1q21 microdeletion syndrome is caused by missing a piece of the hereditary material of the 1st chromosome. In the majority of children, this error occurred in the child itself and was not inherited from either parent. Siblings then have a barely increased chance of also getting the 1q21 microdeletion syndrome themselves. The chance is estimated at about 1% because it cannot be ruled out whether the father has the error in all his sperm cells or the mother in the eggs.
In a small proportion of children, one of the parents is also found to have a 1q21 microdeletion syndrome. In this case, siblings have an increased chance of up to 50% of also having the 1q21 microdeletion syndrome themselves.
A clinical geneticist can provide more information about this.

Prenatal diagnosis
When parents who previously had a child with the 1q21 microdeletion syndrome want to have another child, it is possible during a subsequent pregnancy to perform prenatal diagnostics in the form of a chorionic villus sampling in the 12th week of pregnancy or an amniocentesis in the 16th week of pregnancy. Whether this child will have the same, less or more symptoms as the older brother or sister is difficult to predict. Both procedures have a small risk of causing a miscarriage (0.5% for chorionic villus testing and 0.3% for amniocentesis).

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