Scientists discover rare genetic condition that attacks kids’ immune systems
Partial Trisomy 22 In A Liveborn Resulting From A Rearrangement Between Chromosomes 6 And 22
Editor—We report on a case with an apparent duplication of 22q with an initial karyotype of 46,XY,add(6)(p24).Ish der(6)(6qter→6p24::22q11→22qter)(wcp6+,wcp22+). To our knowledge this is the first report of such an association. We have attempted to characterise the exact regions of duplication using fluorescence in situ hybridisation (FISH) techniques and confirmed that the case is indeed not deleted for chromosome 6 and is only partially trisomic for 22q, thus allowing a more detailed genotype-phenotype correlation than previous studies.
The majority of reports of duplication of chromosome 22 involve the proximal region on 22q. The most common cause of trisomy or tetrasomy of proximal 22q is a de novo supernumerary bisatellited marker chromosome derived from inverted duplication of 22p and 22q11. These supernumerary marker chromosomes have been associated with the cat eye syndrome (CES).1 In contrast, duplications of the distal part of the chromosome 22q region that arise de novo are relatively rare with only eight cases reported so far.2-9 A clinical picture of the distal 22q duplication syndrome has emerged from this limited number of cases comprising growth retardation, shortened life span, congenital heart defects, hypertelorism, narrow palpebral fissures, small nose with anteverted nares, small thorax with hypoplastic nipples, muscular hypotonia, feeding difficulties associated with failure to thrive, and anomalies of the external genitalia in males.5 9
The boy was born at 39 weeks after an uneventful pregnancy to healthy, non-consanguineous, 33 year old parents. It was the second pregnancy; the first pregnancy was spontaneously aborted at 6 weeks' gestation. Family history was normal. Clinical examination at birth showed a proportionately small infant; weight was 1500 g (−4.5 SD), length 39 cm (−5.9 SD), head circumference (OFC) 28.3 cm (−3.7 SD), and chest circumference 25.3 cm (−4.1 SD). He had cyanosis because of persistent fetal circulation, but …
22q Deletion (DiGeorge) Syndrome Clinic
22q11.2 deletion syndrome — also called DiGeorge or velocardiofacial syndrome — is a genetic condition that can affect multiple systems throughout the body, commonly leading to cardiac, endocrine, immunologic, and craniofacial and speech abnormalities, in addition to psychologic and learning difficulties. The name refers to the missing piece of chromosome 22. According to the National Institutes of Health, it occurs in one of 3,000-6,000 births but often is underdiagnosed.
22q Clinic: Why Choose Johns Hopkins All Children'sWe bring together a team of specialists to provide holistic care for patients newborn to 21 years old with 22q deletion syndrome in one specialty clinic.
We have access to experts in more than 50 pediatric specialties and subspecialties to provide individualized care to each patient.
Our genetics experts can analyze and interpret your child's condition.
Our plastic surgery and craniofacial team has vast experience repairing facial anomalies that are common with 22q deletion syndrome.
We have a psychologist embedded within our 22q team to help with behavioral and developmental challenges.
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22q11.2 Deletion Syndrome (DiGeorge Syndrome)
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What Is 22q11.2 Deletion Syndrome (DiGeorge Syndrome)?22q11.2 deletion syndrome is a genetic condition that some babies are born with. A genetic condition happens when there is a problem with a part of a child's DNA. 22q11.2 deletion syndrome can affect many different systems in the body. The problems it causes can range in severity.
22q11.2 deletion syndrome is called 22qDS or 22q for short. Older names for the same genetic difference include DiGeorge syndrome, velocardiofacial syndrome (VCFS), Shprintzen syndrome, conotruncal anomaly face syndrome, and Caylor cardiofacial syndrome.
What Causes 22q11.2 Deletion Syndrome (DiGeorge Syndrome)?People diagnosed with 22q are missing a piece of DNA from the 22nd chromosome. The missing DNA includes several genes that affect how the body develops.
Most often, 22q deletion
syndrome
happens because of a random gene mutation (change) in the early stages of pregnancy. But it also can be inherited (passed down from a parent to their child). What Are the Signs & Symptoms of 22q11.2 Deletion Syndrome (DiGeorge Syndrome)?The body systems affected are different in each person. Some children with 22q will have one or two symptoms, and others will have several more.
Symptoms can include:
Doctors do genetic tests to confirm a diagnosis of 22q. This may happen:
Before birth. If a pregnant woman has a family history of 22q or a prenatal test shows the developing baby could have 22q, the doctor will usually do such tests as:
After a baby is born. If a new baby shows signs of 22q, the doctor will examine the baby and ask about any medical conditions that run in the family.
The doctor may order tests, such as:
Later in life. Some people with 22q are diagnosed when they are older through genetic testing.
How Is 22q11.2 Deletion Syndrome (DiGeorge Syndrome) Treated?Some children may need surgery soon after birth to fix problems related to their heart, breathing, or feeding. All children with 22q need regular visits with a team of specialists to do routine checks.
This team often includes doctors with special training in:
How Can Parents Help?If your child has 22q:
Find a team that specializes in 22q. Not every hospital has all the providers needed to assess and manage a child with 22q. You can look online to find a 22q center at:
Go to all medical visits. Take your child to all scheduled checkups and any follow-up visits with specialists.
Set up therapy care when needed. Help your child build and strengthen life skills. Set up speech therapy and physical therapy visits, or other care that doctors and nurses recommend. If your child has a hard time paying attention, or feels anxious or sad often, ask the doctor if therapy with a mental health provider could help.
Connect with others for support and awareness. Join a 22q support group to find other parents who share similar experiences.
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