22q – An Overview (pdf) (Opens in a new tab)
This document contains slides made by Donna M. McDonald-McGinn, MS, LCGC, the Director of the 22q and You Center at the Children’s Hospital of Philadelphia (CHOP). She is also a Founding Board Member of the International 22q11.2 Foundation.
Summary: This document contains 164 slides with lots of graphics. It starts with a brief lesson on genetics from the cell level to chromosomes and all the way to the genes on the 22q11.2 region. Then it provides a historical perspective on the discovery of 22q11.2 deletion syndrome (22q11.2DS) before discussing the cause and various extents of deletions. The document next offers a large section on the many medical conditions associated with 22q11.2DS and provides patient examples. The final section focusses on 22q11.2 duplication syndrome (22q11.2DupS).
In humans, there are 46 chromosomes in every cell. Cells are the smallest parts of the body. The 46 chromosomes are present in 23 pairs. Chromosomes are the blueprints for the body. One chromosome from each pair comes from the father, and one comes from the mother. This is why a child resembles the entire family.
When we look at the 23 pairs of chromosomes, there are some differences. The first 22 pairs carry most of the information (genes) that makes us who we are. The 22nd chromosome is the smallest. The 23rd pair determines whether a baby will be male or female.
If a baby has a 22q11.2 deletion syndrome this means that a small amount of information (about 30 genes) is missing from the 22nd chromosome. When it is suspected that a baby might have this diagnosis, a special test will be ordered to look for it. This deletion is present from the moment that the mother’s egg and the father’s sperm come together to make the baby. There is nothing that the parents said or thought or did that causes this to happen. It is not due to illnesses, medications, food, drink, cigarettes, or drugs used by the parents before or during or after the pregnancy. In most families, the birth of a baby with the 22q11.2 deletion is the first time that this has happened in the family. However, in about one in ten families the deletion is present because one of the parents has it as well and passed it to the child either in the one egg or one sperm that went to form the baby. Therefore, it is recommended that both parents have the blood test when the 22q11.2 deletion is found in their child to help the parents better understand what the chance is of having another child with the deletion.
While the health effects of the 22q11.2 deletion vary from patient to patient, the common medical findings may include the following:
- Congenital Heart Defects are present in about 74% of affected individuals. Specifically they most often include: Tetralogy of Fallot (TOF), Interrupted Aortic Arch (IAA), Ventricular Septal Defects (VSD), Truncus Arteriosis (TA), a vascular ring, and other aortic arch differences. Most congenital heart differences are now treatable surgically. (Consult a Cardiologist.)
- Immune System Problems occur in about 75% of children with the 22q11.2 deletion due to problems in a gland called the thymus, located near the heart. The thymus gland helps to fight infection. However, most people with the deletion do well despite their immune differences. (Consult an Immunologist.)
- Hypocalcemia (or low calcium) is common, especially in the newborn period, but it can occur anytime, including during growth spurts, puberty, during an illness, or around the time of an operation. It can be treated, usually by a hormone doctor. (Consult an Endocrinologist.)
- Palatal Differences (affecting the roof of the mouth) occur in about 70% of children with the 22q11.2 deletion. Only 10% will have a hole in the roof of the mouth (cleft palate), and 1% may also have a cleft lip. However, the most common problem with the palate, which occurs during speech and feeding, is a difference called velopharyngeal incompetence (VPI). VPI affects the way the palate divides the mouth from the nose. This is more difficult to diagnose than a cleft, as it may only show itself when there is vomiting through the nose or speech that sounds “hypernasal” (like the sound is escaping through the nose). This is usually treatable. A Pediatric Plastic Surgeon or an Ear Nose Throat doctor (ENT) should be consulted.
In general, young children with the 22q11.2 deletion syndrome have delays in sitting and walking. They generally walk at about 18 months of age. They have delays in babbling, saying their first words, and speaking in sentences. In fact, there are many children with the deletion who are still not speaking at two and three years of age.
About 20% of children with the 22q11.2 deletion have an autism spectrum disorder which affects the way they interact, develop, and communicate. In addition, some children may have behavioral differences such as ADHD (attention deficit hyperactivity disorder), OCD (obsessive-compulsive disorder), and anxiety.
How can these problems be managed?
Just as every typical child is different, every child with the 22q11.2 deletion will have different medical and developmental needs. With this in mind, children with the deletion need care by appropriate specialists, but in addition, it is often helpful to be seen by a medical team to receive coordinated care. While there is no “cure” for the 22q11.2 deletion, there are ways to manage the problems it causes, and the earlier the symptoms are detected the better.
Intervention can come in one of two ways: private therapy, with or without insurance coverage, or early intervention services through the state or county. Early intervention can be requested by a pediatrician or other health care provider or directly by parents. The evaluation includes a team approach with specialists involved from speech and language therapy, physical therapy (PT), occupational therapy (OT), special education, etc. If a child qualifies, the services are generally free of charge, depending upon your state of residence. If your child does not qualify, you may want to consider private therapies. In addition, children can always be reevaluated later, as in many states, there are two age defined programs offered: Birth to 3 years and 3 – 5 years. Children enrolled in Early Intervention will have a written plan of services and goals. Parents should be invited to participate in meetings to develop these goals. Parents are partners with the professionals in writing these developmental goals for the child. It may be intimidating to be with multiple professionals, so it is wise to bring along a friend, spouse or other relative, as it is always useful to have another set of eyes and ears.
Our son, John, is a happy, funny, and lovable eight year old who enjoys his trains, computer games and occasionally tormenting his little sister. When we look back and think about the hours of waiting during his two open-heart surgeries, his difficult birth, and his month-long stay at Children’s Hospital, it’s almost impossible to comprehend that it has just been eight years. John has been through a lot in his short life, but he has always been a trooper. We often think about how relaxed and comfortable he is for every doctor’s appointment or hospital visit. No matter what he has to face, he makes the best of it. John has changed and developed so much in eight years, which has been at times joyous and at other times difficult. A lesson worth learning for us has been that when things get difficult, we always think back over those eight years. We reflect on all that John has been through, and try to focus on all the progress he has made. We can’t predict the future, and we know that John has many hurdles to overcome down the road, but at this stage, we try to take every day as it comes and enjoy each day.
Evidence-based Medical and Therapeutic Intervention? Who Needs It?
A discussion for parents of children with special developmental needs about evidence, consensus and anecdotal-based interventions
by Robert M. Miller
After more than four decades of working with parents of children with special developmental needs, I’ve learned that they often find it difficult to know what the best approaches or interventions are to help their children. Conflicting statements, recommendations and opinions from fellow parents and/or from professionals involved in the child’s treatment can cause confusion and uncertainty. Understanding why there can be such variation within always well-meaning advice may help parents make the difficult decisions that confront them.
The International Brain Behavior Consortium
An International Consortium Receives 12 Million Dollars from The National Institutes of Health in the United States of America to Study the Brain and Behavior in Individuals with 22q11.2 Deletion Syndrome.
The following papers and links are technical in nature and are provided for informational purposes only, including for sharing with your child’s treatment professionals. Readers are reminded of our Medical Disclaimer.