Introduction
22q11.2 Deletion Syndrome (also known as Velocardiofacial Syndrome, DiGeorge Syndrome, Shprintzen Syndrome, Catch-22 Syndrome and more colloquially as '22q') affects about 1 in 4,000 children. The way this condition affects individual children is very variable, which is one of the reasons it was described initially as different diagnoses. The underlying cause is a small missing portion of a chromosome, one of the packages of DNA in our cells.
As a result of this altered chromosome, patients with 22q can develop several problems including heart defects at birth, cleft palate, difficulty in feeding, with speech and with learning, a lowered immune system, reduced hearing, difficulty maintaining the right amount of Calcium in the blood and altered facial features, which are generally fairly subtle. |
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A multidisciplinary approach from birth to adulthood is essential in order to provide the best opportunities for patients with 22q. As Director of the UT Southwestern 22q clinic, I strive to provide my patients with this multidisciplinary approach to their care. As the condition is so varied in the way it affects children, treatment is individualized with regular assessments of the different aspects of the medical condition itself but also assessing and providing services and support to optimize speech development and to ensure the best learning environment for the child.
Feeding and Speech
A cleft palate is a hole in the roof of the mouth and, if there is one, this can cause problems with feeding immediately after birth. While most children with a cleft palate will be able to feed well using a special type of bottle, it is important that the child is assessed shortly after birth by a feeding therapist experienced with children with a cleft palate and 22q. If there is a cleft palate, I tend to repair this at 9-12 months of age. Please see my Cleft Palate Speech information for more details on speech associated with a cleft palate. Children with velocardiofacial syndrome often struggle to co-ordinate the various components of the speech mechanism and most will need speech therapy to optimize their speech, even without a cleft palate.
In Depth
22q11.2 Deletion Syndrome is the most complete and descriptive name for this condition, which is caused by a small missing portion of a chromosome. The DNA in people is stored in 46 packages of groups of genes and each of these packages is known as a chromosome. The description of 22q11.2 means that the missing piece is on chromosome number 22 and it is missing from the position ‘q11.2’. Chromosome number 22 contains about 1,100 genes and in this condition, about 30 are missing.
This syndrome affects about 1 in 4,000 children and most children affected by this condition do not have it passed from either parent. People with the condition can, however, can pass it on to their children and the way it is passed on is called autosomal dominant, which means that there is a 50% chance of passing on the condition to each child.
Diagnosis is made by a combination of the clinical assessment and a lab test, known as a ‘FISH 22’ or ‘Chromosomal MicroArray’. This test looks specifically for the missing genes on chromosome 22 and can confirm the presence of the missing genes. What it can’t predict is the how those missing genes will affect the child.
Because it was originally described as different conditions by different people, it is difficult to say who first described it, but DiGeorge Syndrome was described by Angelo DiGeorge in 1968 and Velocardiofacial Syndrome was described by Robert Shprintzen in 1978. Many people still consider the condition as two separate entities, giving the name DiGeorge Syndrome to patients who have mainly immunological problems from the condition and using the name Velocardiofacial Syndrome to patients who have heart defects at birth.
Heart defects can be in the form of septal defects, when there is a ‘hole in the heart’ between the left and right sides, persistent truncus arteriosus, which is when there is a single artery out of the heart instead of one to the lungs and one to the rest of the body, interrupted aortic arch, in which the main artery carrying blood to the lower half of the body has a missing section, and Tetralogy of Fallot, in which there is a series of heart defects because of an imbalance between the two sides of the heart. The end result of these is that the amount of oxygen carried around the body by the blood is reduced and surgery at a young age is often required.
Failure of the immune system in this condition is rare, although a degree of malfunction is seen fairly frequently, which means that infections can be harder to fight. This is because of a gland in the lower neck called the Thymus, which has an important role in childhood. It allows certain immune cells known as ‘T-cells’ to mature, and with a poorly functioning Thymus, these cells do not work as well as they should in early years. Before adulthood, the Thymus tends to shrink away and other parts of the body take over its function. Most children with this condition, who have a degree of immune malfunction, tend to have a poorly functioning Thymus, but the immune malfunction in early years tends to improve over time as other parts of the body take over that role. Along with the poorly functioning Thymus, children with this condition can have problems with maintaining the correct amount of Calcium in the blood because the glands that control this, the parathyroid glands also often do not work well. This can result in a variety of problems with bones, hair, nails, skin and teeth.
Children with this condition can have difficulties with learning, which can be due to problems with hearing, behavioral issues, because IQ tends to be within the low end of the normal range, or because of a combination of these factors. Although most people with velocardiofacial syndrome will not develop psychiatric illness, there is a higher chance of having psychiatric problems than in people without velocardiofacial syndrome.
The face of children with velocardiofacial syndrome tend to show some characteristic features, although these tend to be fairly subtle. Most parents don’t notice them until they attend a clinic or group with other children who have the condition, when they will start to notice some similarities between the children. The features can include flatness over the cheekbone area, a broad bridge of the nose with a wide or round tip of the nose, ears lower on the head than expected, often with a more square or notched shape to the upper part of the ear, eyelids that slant downwards to the outside of the face with eyelids that can form a hood over the eyelashes, eyes that are unusually widely set apart and a mouth that is slightly open at rest.
It is difficult to say how children will be affected by the condition and what they can expect throughout their childhood as individual children are affected in very different ways both in terms of which parts of the body are affected and also how severely they are affected.
Ongoing care from infancy to adulthood is important for a complex syndrome, such as velocardiofacial syndrome and we recommend that a child with this syndrome is cared for in the context of a Multi-Disciplinary Team so that there is regular in-house review by the multiple health care professionals that will be required as the child grows, and this is what we offer at Children’s.
This syndrome affects about 1 in 4,000 children and most children affected by this condition do not have it passed from either parent. People with the condition can, however, can pass it on to their children and the way it is passed on is called autosomal dominant, which means that there is a 50% chance of passing on the condition to each child.
Diagnosis is made by a combination of the clinical assessment and a lab test, known as a ‘FISH 22’ or ‘Chromosomal MicroArray’. This test looks specifically for the missing genes on chromosome 22 and can confirm the presence of the missing genes. What it can’t predict is the how those missing genes will affect the child.
Because it was originally described as different conditions by different people, it is difficult to say who first described it, but DiGeorge Syndrome was described by Angelo DiGeorge in 1968 and Velocardiofacial Syndrome was described by Robert Shprintzen in 1978. Many people still consider the condition as two separate entities, giving the name DiGeorge Syndrome to patients who have mainly immunological problems from the condition and using the name Velocardiofacial Syndrome to patients who have heart defects at birth.
Heart defects can be in the form of septal defects, when there is a ‘hole in the heart’ between the left and right sides, persistent truncus arteriosus, which is when there is a single artery out of the heart instead of one to the lungs and one to the rest of the body, interrupted aortic arch, in which the main artery carrying blood to the lower half of the body has a missing section, and Tetralogy of Fallot, in which there is a series of heart defects because of an imbalance between the two sides of the heart. The end result of these is that the amount of oxygen carried around the body by the blood is reduced and surgery at a young age is often required.
Failure of the immune system in this condition is rare, although a degree of malfunction is seen fairly frequently, which means that infections can be harder to fight. This is because of a gland in the lower neck called the Thymus, which has an important role in childhood. It allows certain immune cells known as ‘T-cells’ to mature, and with a poorly functioning Thymus, these cells do not work as well as they should in early years. Before adulthood, the Thymus tends to shrink away and other parts of the body take over its function. Most children with this condition, who have a degree of immune malfunction, tend to have a poorly functioning Thymus, but the immune malfunction in early years tends to improve over time as other parts of the body take over that role. Along with the poorly functioning Thymus, children with this condition can have problems with maintaining the correct amount of Calcium in the blood because the glands that control this, the parathyroid glands also often do not work well. This can result in a variety of problems with bones, hair, nails, skin and teeth.
Children with this condition can have difficulties with learning, which can be due to problems with hearing, behavioral issues, because IQ tends to be within the low end of the normal range, or because of a combination of these factors. Although most people with velocardiofacial syndrome will not develop psychiatric illness, there is a higher chance of having psychiatric problems than in people without velocardiofacial syndrome.
The face of children with velocardiofacial syndrome tend to show some characteristic features, although these tend to be fairly subtle. Most parents don’t notice them until they attend a clinic or group with other children who have the condition, when they will start to notice some similarities between the children. The features can include flatness over the cheekbone area, a broad bridge of the nose with a wide or round tip of the nose, ears lower on the head than expected, often with a more square or notched shape to the upper part of the ear, eyelids that slant downwards to the outside of the face with eyelids that can form a hood over the eyelashes, eyes that are unusually widely set apart and a mouth that is slightly open at rest.
It is difficult to say how children will be affected by the condition and what they can expect throughout their childhood as individual children are affected in very different ways both in terms of which parts of the body are affected and also how severely they are affected.
Ongoing care from infancy to adulthood is important for a complex syndrome, such as velocardiofacial syndrome and we recommend that a child with this syndrome is cared for in the context of a Multi-Disciplinary Team so that there is regular in-house review by the multiple health care professionals that will be required as the child grows, and this is what we offer at Children’s.