Overview

Individuals with 22q11.2 deletion syndrome have a wide range of clinical presentations, and the manifestations may vary among affected individuals within the same family. Some presentations are obvious and life-threatening (e.g., DiGeorge syndrome), whereas others may be more subtle (palate incompetence and learning problems). Because of the variety of clinical presentations, many different names have been given to syndromes that have turned out to be due to 22q11.2 deletion, including DiGeorge syndrome (DGS), velocardiofacial syndrome (VCFS), and Shprintzen syndrome. Common clinical manifestations include:

• Characteristic facial features
• Congenital heart disease (particularly conotruncal malformations)
• Palatal abnormalities
• Hypocalcemia
• Feeding problems
• Gastroesophageal reflux
• Chronic otitis media
• Developmental delay/cognitive problems (especially in the areas of expressive language)
• Behavioral, emotional, and psychiatric issues
• Immune dysfunction

Since all abnormalities associated with the syndrome may occur independently, it is the cluster of symptoms that should trigger suspicion of this diagnosis. Medical home clinicians should be watchful for children with subtle presentations. [Shooner: 2005] Less common features are described in the Presentations section, below.

Prevalence

Once thought to be an uncommon diagnosis, prevalence of 22q11.2 deletion syndrome is now estimated at 1:4,000. [McDonald-McGinn: 2011]

Genetics

22q11.2 deletion syndrome is inherited in an autosomal dominant fashion, although approximately 90% of cases are not inherited and occur secondary to a spontaneous chromosome deletion. This region is estimated to contain about 30 to 40 genes. The genes COMT and TBX1 are of particular interest as they may contribute significantly to the phenotype. Another diagnostic approach gaining popularity is CGH (comparative genomic hybridization). See 22q11.2 Deletion Syndrome (GeneReviews) for more detail.

Prognosis

22q11.2 deletion syndrome is a lifelong condition. Life expectancy may be affected, particularly if a severe heart defect exists. The degree of intellectual disability will determine the individual's ability to function independently as an adult.

Practice Guidelines

Roles of the Medical Home

The medical home is particularly important in the management of children with genetic syndromes. Regularly scheduled care management visits should be considered to allow adequate time to discuss syndrome-associated developmental and medical issues. These include screening for associated complications, referring to appropriate subspecialists when needed, providing a comprehensive medical history in case of emergency, providing immunizations, monitoring developmental and educational progress and interventions, and providing routine anticipatory guidance and advocacy for the child. Due to the wide variability of clinical presentations, it is important that genetic counseling be a part of ongoing management. [Shooner: 2005] [McDonald-McGinn: 2001]

Pearls & Alerts for Assessment

A compilation of important cautions and considerations can be found at Recommended Assessments for 22q11.2 Deletion Syndrome [Bassett: 2011].

Hypocalcemia

Persistent hypocalcemia, even in older individuals, should lead to consideration of 22q11.2 deletion syndrome. [Hiéronimus: 2006] Mild hypocalcemia may manifest as muscle cramping, shortness of breath secondary to bronchospasm, distal extremity numbness, tingling sensations, cataracts, dry skin, coarse hair, brittle nails, psoriasis, chronic pruritus, and poor dentition. Acute hypocalcemia may result in tetany, syncope, seizures, and cardiovascular compromise. Maintain a low threshold for testing serum calcium levels (ionized calcium is preferred) when the patient is symptomatic, or initiate screening during periods of acute physiologic stress, such as severe illness, significant trauma, and surgery.

Autism spectrum disorder (ASD)

In a study by [Fine: 2005], 14% of children with 22q11.2 deletion syndrome qualified for diagnosis of ASD.

Bleeding problems

Idiopathic thrombocytopenia purpura (ITP) occurs 200 times more frequently in individuals with 22q11.2 deletion than in the general population. Individuals with 22q11.2 deletion syndrome may also have Bernard-Soulier syndrome (BSS), which is an autosomal recessive disorder that results in giant platelets and thrombocytopenia. Children with BSS often have difficulty with excessive bleeding during surgical procedures. The clinical syndrome of BSS may result from a mutation in any of 4 genes; one lies in the region that is commonly deleted in 22q11.2 deletion syndrome (GP1BB ). In an individual with 22q11.2 deletion syndrome, one of these genes is absent. If the other allele carries a mutation, there will be no functional copy of BSS and a bleeding diathesis would exist.

For the Condition

Prenatal diagnosis of 22q11.2 deletion syndrome is possible through fluorescent in situ hybridization (FISH) testing on samples from chorionic villus sampling (CVS) or amniocentesis and, in some cases, by diagnostic ultrasound. FISH or comparative genomic hybridization (CGH) testing in low-risk pregnancies (those with no family history) should also be considered if prenatal ultrasound demonstrates Robin anomaly and/or congenital heart disease. Prenatal diagnosis, even if performed late in pregnancy, may help with expectant management of the newborn. [Driscoll: 2001]

Of Family Members

Most children with 22q11.2 deletion syndrome have de novo mutations, yet 5-10% will have inherited the syndrome from a parent. Although dilation by an experienced clinician may be sufficient to rule out the diagnosis, parents should consider being screened for the syndrome, particularly when clinical evaluation is equivocal or when a diagnosis is suspected.

For Complications

Consider screening for:

• Cardiac defects - all individuals with 22q11.2 deletion syndrome should have screening echocardiography around the time of their initial diagnosis
• Significant renal anomalies upon confirmation of diagnosis
• Hypocalcemia in the neonatal period, in times of physiologic stress, prior to elective surgery, and when signs and symptoms suggest this complication
• Thrombocytopenia when there is a history of easy bruising, prolonged bleeding, recurrent epistaxis, and elective surgery exists
• Visual and hearing impairments annually - because of chronic middle ear effusions, a low threshold for referral to pediatric otolaryngology should be maintained
• Dental/enamel weakness - refer to pediatric dentistry after 12 months of age because of relatively high incidence
• Cervical spine abnormalities - Children with 22q11.2 deletion syndrome are more likely than the general population to have cervical flexion/extension instability. Screening 6-view cervical spine X-rays (AP, lateral, open mouth, flexion, and extension) are recommended at age 4, when the bones ossify, by some investigators. [22q11.2 Deletion Syndrome (GeneReviews)]
• Periodic developmental and neuropsychological screenings should be considered, particularly speech and language assessments. Mental health screening should be routine for adolescents because of increased incidence of schizophrenia, bipolar disorder, anxiety, and depression.

Screening for immunodeficiency is controversial. Although it is a feature of the classic DiGeorge phenotype, immunodeficiency is rare even in this condition. Immunodysfunction is more common, but it does not require special diagnostic testing and rarely influences medical management. Testing for immunodeficiency should be considered in cases of lymphocytopenia and with a clinical history of atypical or recurrent serious infection. These tests are best ordered and interpreted by an immunologist, but because the results rarely appropriately alter medical management for most of the population affected by chromosome 22q11.2 deletion syndrome, T cells subsets and/or immunodeficiency panels should not be routinely used.

Presentations

22q11.2 deletion syndrome has a highly variable phenotype with respect to clinical severity. Infants presenting with major congenital heart defects, hypocalcemia, and immunodeficiency were said to have "DiGeorge syndrome." Children presenting as toddlers or preschoolers in cleft palate clinics with developmental delays or with learning and behavior problems were said to have velocardiofacial or Shprintzen syndrome. Since presentations may be subtle and vary widely, it is possible for offspring of mildly affected parents to have life-threatening problems. The following lists general characteristics:

Most common:

• Palatal abnormalities, especially velopharyngeal insufficiency (due to underdevelopment of the soft tissues of the palate), and/or velopharyngeal incompetence (the tissue is present but does not perform satisfactorily), which is often associated with a nasal voice. Abnormalities may range from submucosal or obvious cleft palate to subtle signs of velopharyngeal insufficiency (VPI) and/or oromotor apraxia. VPI may occur independently in children with this syndrome, or it may follow cleft palate repair.
• Congenital heart disease, especially conotruncal malformations, is seen in roughly 50% of affected individuals and is responsible for most of the mortality associated with this syndrome. Malformations include tetralogy of Fallot, interrupted aortic arch type B, ventricular septal defect, truncus arteriosus, and others.
• Learning problems, developmental delay, and/or IQ scores in the low average, borderline, or mildly/moderately intellectually disabled range. Many children will have an unusual pattern with higher verbal than performance scores.
• Feeding and swallowing difficulties, present in about 30% of children with 22q11.2 deletion syndrome, may lead to nasogastric or gastrostomy tube placement.
• Affected individuals are likely to be smaller than their gender-matched siblings, although they typically are within the normal range on standard growth curves.
• Characteristic facial features may be variable but include hooding of the eyes, short palpebral fissures, a broad nasal root, a bulbous nasal tip, midface hypoplasia, a small chin (although prognathism is commonly found in adults), abnormal development of the perioral region giving rise to an asymmetric smile or grimace, and dysplasia of the auricles. See Pictures of Typical Facial Appearance [Shprintzen: 2008] for examples.
• Immune dysfunction - more vulnerable to infection, but not usually requiring special measures of intervention) due to thymic hypoplasia. Immunodeficiency has also been described, but this especially rare.)
• Hypocalcemia due to parathyroid dysfunction
• Mental health problems (commonly mild manifestations of anxiety and maladaptive behaviors) are seen in over 50% of individuals
• Kidney/genitourinary tract anomalies
• Dental problems due to enamel deficiency

Less common:

• Skeletal problems, including polydactyl, extra ribs, hemivertebrae, craniosynostosis (Cranial Deformation and Craniosynostosis)
• Laryngotracheal-esophageal structural defects, such as webs and vascular rings
• Eye abnormalities, including ptosis, colobomas, cataracts, strabismus
• CNS abnormalities are many and varied
• Gastrointestinal malformations
• Hearing loss, both conductive and sensorineural
• Various autoimmune diseases, including juvenile idiopathic arthritis, Graves' disease, Hashimoto thyroiditis, vitiligo, thrombocytopenia
• Growth hormone deficiency

Diagnostic Criteria

Though clinical findings were previously used to make the diagnosis of 22q11.2 deletion syndrome, it is now based on genetic testing.

Differential Diagnosis

22q11.2 deletion syndrome is the most common syndrome associated with velopharyngeal insufficiency. The syndrome is also highly associated with conotruncal cardiac defects and should be tested for in children with these defects. [Goldmuntz: 2005]

If 22q11.2 syndrome is suspected clinically and FISH testing is negative, it is possible that there is a microdeletion not apparent in standard testing or a deletion of another untested region (10p13-p14) nearby. Manifestations of non-specific forms of aneuploidy may also overlap with those of 22q11.2 deletion syndrome. A geneticist may recommend additional testing to be performed in a reference or research laboratory.

Children with Smith-Lemli-Opitz syndrome may share some of the features of 22q11.2 deletion syndrome, but they typically have a serum cholesterol <50 and elevated serum concentration of 7-dehydrocholesterol or an elevated 7-dehydrocholesterol:cholesterol ratio.

Children with VATER association and Goldenhar syndromes may clinically resemble those with 22q11.2 deletion syndrome - unfortunately, no diagnostic testing is yet available to confirm those diagnoses.

The phenotypes of fetal alcohol syndrome, CHARGE syndrome, and isotretinoin embryopathy may overlap with that of 22q11.2 deletion syndrome.

Comorbid & Secondary Conditions

Immune problems in 22q11.2 deletion syndrome range from total absence of the thymus to a typical response to infection. Most children will only require monitoring for and early aggressive treatment of infections; in rare cases, other measures may be necessary (IVIG therapy, thymus transplantation). 22q11.2 Deletion Syndrome (GeneReviews) See the Screening section, above.

More than half of the individuals with 22q11.2 deletion syndrome are estimated to have some abnormality of their cardiac system. Cardiac abnormalities account for the majority of early deaths in children with this syndrome. The 3 major defects are tetralogy of Fallot, interrupted aortic arch, and ventricular septal defects; others are possible. See the Screening section, above.

Children with 22q11.2 deletion syndrome are more likely than the general population to have cervical flexion/extension instability. See the Screening section, above.

Although rare, autoimmune disorders such as juvenile idiopathic arthritis, hypo- and hyperthyroidism, and celiac disease are more common in individuals with 22q11.2 deletion than in the general population.

Current & Past Medical History

Ask about the child's history of infections, constipation, feeding problems, and pneumonia. Feeding problems are common, including reflux and difficulty with sucking/swallowing, especially with liquids. Frequent episodes of otitis or sinusitis may be due to regurgitation of food into the nasal cavity due to velopharyngeal insufficiency. Ask about voice quality.

Family History

The majority of 22q11.2 deletion syndrome occurs sporadically, but ask about other family members with similar facial features, heart defects, a nasal voice, palate anomalies, and learning problems.

Pregnancy/Perinatal History

Some clinical signs of 22q11.2 deletion syndrome may be obvious on prenatal ultrasound (e.g., congenital heart disease, Robin anomaly, renal anomalies). Perinatal period may be complicated by hypocalcemia and congenital heart disease.

Developmental & Educational Progress

Developmental delay, impaired cognitive abilities, psychiatric problems, and features of anxiety disorder, ADHD, and autistic spectrum disorder are relatively common. Children with intellectual disability may develop behavior problems.

Social & Family Functioning

Assess family functioning and resources. Family functioning may be increasingly challenged by the child's intellectual and/or behavioral difficulties. This dynamic is significantly more challenged in families when a parent is personally affected by chromosome 22q11.2 syndrome.

Physical Exam

Sensory Testing

Following diagnosis of 22q11.2 deletion syndrome, sensory testing should include evaluation for hearing loss and vision abnormalities. Evaluation of hearing may be indicated if there have been frequent or persistent ear infections, especially if speech development is delayed.

Laboratory Testing

If clinically indicated, test for hypocalcemia (serum ionized calcium concentration) and immune function (absolute lymphocyte count, with T- and B-cell subsets if low). Although hypocalcemia usually presents in infancy, it may occur in older individuals, particularly during puberty and during illnesses. 22q11.2 Deletion Syndrome (GeneReviews)

Thyroid dysregulation should be suspected if the individual is symptomatic. [Choi: 2005] Although no clear guideline exists, periodic screening for thyroid dysregulation should be performed (T4, TSH). In children with height below the 2nd percentile, consider checking levels of growth factors IGF1 and IGF-BP3.

Some investigators also recommend testing for immune system deficiencies. 22q11.2 Deletion Syndrome (GeneReviews)

Imaging

All individuals newly diagnosed with 22q11.2 deletion syndrome should have a CXR, EKG, and echocardiogram and/or chest MRI. 22q11.2 Deletion Syndrome (GeneReviews)

A renal ultrasound should also be considered; renal anomalies may be found in as many as 30% of individuals.

A one-time brain MRI may identify CNS abnormalities. Although no large population studies have been performed, a study found minor cerebellar abnormalities in up to 1/3 of affected children. [Robin: 2006] Polymicrogyria, enlarged ventricles, heterotopias, and other abnormalities have also been described. [Gerkes: 2010]

Seizures, usually associated with hypocalcemia, occur in a small percentage of individuals. Consider an EEG if there is a medical history consistent with seizure, especially in the absence of documented hypocalcemia.

Consider X-rays (spine/chest) for vertebral anomalies.6 -view cervical spine X-rays are recommended at age 4, when the bones ossify, by some experts, to look for cervical instability. 22q11.2 Deletion Syndrome (GeneReviews)

A swallow study may be helpful if there are symptoms of nasal regurgitation of food, coughing or choking when drinking, or other signs of swallowing problems.

Genetic Testing

FISH testing for 22q11.2 deletion syndrome should be obtained, as well as a genetics consultation. Depending on the reference lab or clinical presentation, CGH may also be used.

Other Testing

Speech and language assessment can be helpful in the diagnosis of velopharyngeal insufficiency and oromotor apraxia.

Overview

Clinical management of individuals with 22q11.2 deletion syndrome varies with the severity of the clinical features and the age of the child. Early in life, the focus tends to be on acute medical problems, including heart disease, frequent infections, feeding problems, and those associated with palatal dysfunction. Delays in the achievement of developmental milestones deserve identification and attention. After the child reaches school age, the focus shifts to cognitive and behavioral problems. Multisystem Features of 22q11.2 Deletion Syndrome [Bassett: 2011] presents a chart of common features and management considerations by age.

Pearls & Alerts for Treatment & Management

Caution with live virus vaccines

Caution should guide the use of live virus vaccines in individuals who manifest immunocompromise. Do not confuse immunodysfunction with immunocompromised/immunodeficiency. Otherwise, children with 22q11.2 deletion syndrome should follow the same immunization schedule as the rest of the pediatric population. [Perez: 2003]

Considerations with hospital admissions

Irradiated and cytomegalovirus-seronegative blood components have been recommended for infants who need blood products, since immunodeficiency may be present. Standard precautions can be employed in individuals without immunodeficiency. Check ionized calcium in children who are admitted to the hospital for illness, or in conjunction with major surgeries. [Jatana: 2007]

Abnormal carotid artery locations

Affected individuals may have abnormally located carotid arteries, usually closer to the nasopharynx than usual. This needs to be considered by otolaryngologists planning palatal surgeries.

Growth or Weight Gain

Maintain vigilance in screening for pathologic etiologies of poor growth, and provide counseling to parents to help navigate growth issues. Adolescents and young adults typically suffer from decreased physical activity and are more likely to be overweight or obese.

Development (Cognitive, Motor, Language, Social-Emotional)

Plan for delays, especially in language development. Hypotonia may delay gross motor milestones, yet improvement usually occurs before the children are eligible for services. Learning disabilities are common and should be anticipated; individualized education programs (IEPs) and learning and testing aides can help. Encourage families to indoctrinate socialization strategies early since affected individuals can be marginalized by peers and develop poor self-esteem.

Systems

On the Web

22q11.2 Deletion Syndrome (GeneReviews)
Clinical characteristics, diagnosis/testing, management, genetic counseling, and molecular pathogenesis; from the University of Washington and the National Library of Medicine.

Velocardiofacial Syndrome (OMIM)
Information about clinical features, diagnosis, management, and molecular and population genetics; Online Mendelian Inheritance in Man, authored and edited at the McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine

Helpful Articles

PubMed search for articles in the last year about 22q11.2 deletion syndrome in children

Bassett AS, McDonald-McGinn DM, Devriendt K, Digilio MC, Goldenberg P, Habel A, Marino B, Oskarsdottir S, Philip N, Sullivan K, Swillen A, Vorstman J.
Practical guidelines for managing patients with 22q11.2 deletion syndrome.
J Pediatr. 2011;159(2):332-9.e1. PubMed abstract / Full Text

Carotti A, Digilio MC, Piacentini G, Saffirio C, Di Donato RM, Marino B.
Cardiac defects and results of cardiac surgery in 22q11.2 deletion syndrome.
Dev Disabil Res Rev. 2008;14(1):35-42. PubMed abstract

Pereira E, Marion R.
Chromosome 22q11.2 deletion syndrome.
Pediatr Rev. 2015;36(6):270-2; discussion 272. PubMed abstract / Full Text

Schneider M, Debbané M, Bassett AS, Chow EW, Fung WL, van den Bree M, Owen M, Murphy KC, Niarchou M, Kates WR, Antshel KM, Fremont W, McDonald-McGinn DM, Gur RE, Zackai EH, Vorstman J, Duijff SN, Klaassen PW, Swillen A, Gothelf D, Green T, Weizman A, Van Amelsvoort T, Evers L, Boot E, Shashi V, Hooper SR, Bearden CE, Jalbrzikowski M, Armando M, Vicari S, Murphy DG, Ousley O, Campbell LE, Simon TJ, Eliez S.
Psychiatric disorders from childhood to adulthood in 22q11.2 deletion syndrome: results from the International Consortium on Brain and Behavior in 22q11.2 Deletion Syndrome.
Am J Psychiatry. 2014;171(6):627-39. PubMed abstract / Full Text

Shprintzen RJ.
Velo-cardio-facial syndrome: 30 Years of study.
Dev Disabil Res Rev. 2008;14(1):3-10. PubMed abstract / Full Text

Toolkits

Health Care for Adults with Intellectual & Developmental Disabilities - Toolkit for Clinicians (Vanderbilt)
Health Watch Tables and checklists for autism, Down syndrome, fragile X, Prader-Willi, Williams syndrome, and 22q11.2 deletion syndrome. Developed for primary care providers of adults with developmental and intellectual disabilities; Kennedy Center for Excellence in Developmental Disabilities.

Information on the Web

22q11.2 Deletion Syndrome (MedlinePlus)
Information for families that includes description, frequency, causes, inheritance, other names, and additional resources; from the National Library of Medicine.

Velocardiofacial Syndrome (Genome.gov)
Medical information, educational materials, and a link to the genetic and rare disease information center; National Human Genome Research Institute.

22q11.2 Deletion Syndrome Educational Videos (MIND)
Videos about 22q11.2 deletion syndrome that cover early childhood and adolescence; University of California at Davis Medical Investigation of Neurodevelopmental Disorders Institute.

22q11.2 Deletion Syndrome (GARD)
Includes information about symptoms, inheritance, diagnosis, finding a specialist, related diseases, and support organizations; Genetic and Rare Diseases Information Center of the National Center for Advancing Translational Sciences.

Chromosome 22q11.2 Deletion Syndrome (NORD)
Information for families that includes synonyms, signs & symptoms, causes, affected populations, related disorders, diagnosis, therapies (both standard and investigational), and support organizations; National Organization of Rare Disorders.

National & Local Support

International 22q11.2 Foundation
Extensive resources and support services for families and clinicians caring for those with 22q11.2 deletion syndrome.

Studies/Registries

Clinical Trials Related to 22q11.2 Deletion Syndrome (clinicaltrials.gov)
Studies looking at better understanding, diagnosing, and treating this condition; from the National Library of Medicine.

Services for Patients & Families in Nevada (NV)

Service Categories	# of providers* in:	NV	NW	Other states (4)  (show)		NM	OH	RI	UT
Developmental - Behavioral Pediatrics		2	1		2	2	12	9
Early Intervention for Children with Disabilities/Delays		32	3		35	3	14	55
General Counseling Services		209	1		3	1	30	362
Genetic Testing and Counseling		12	5		5	6	7	12
Head Start/Early Head Start		58	1		7	2	19	32
Medical Genetics		5	1		2	1	4	8
Neuropsychiatry/Neuropsychology		5			1		9	9
Pediatric Cardiology		4			2		17	5
Pediatric Endocrinology		6	1		4	1	13	4
Pediatric Gastroenterology		6	1		3	1	19	4
Pediatric Immunology		1			3		6	6
Pediatric Ophthalmology		6	1		6	1	8	4
Pediatric Orthopedics		8	4		6	4	16	21
Pediatric Otolaryngology (ENT)		5	1		8	1	7	10
Pediatric Plastic Surgery		4	3		5	3	4	5
Preschools		30			4		11	79
Psychiatry/Medication Management		49			2		79	56
School Districts		22			90	1	63	47
Speech - Language Pathologists		13	4		22	4	31	69

For services not listed above, browse our Services categories or search our database.

* number of provider listings may vary by how states categorize services, whether providers are listed by organization or individual, how services are organized in the state, and other factors; Nationwide (NW) providers are generally limited to web-based services, provider locator services, and organizations that serve children from across the nation.

Bassett AS, McDonald-McGinn DM, Devriendt K, Digilio MC, Goldenberg P, Habel A, Marino B, Oskarsdottir S, Philip N, Sullivan K, Swillen A, Vorstman J.
Practical guidelines for managing patients with 22q11.2 deletion syndrome.
J Pediatr. 2011;159(2):332-9.e1. PubMed abstract / Full Text

Carotti A, Digilio MC, Piacentini G, Saffirio C, Di Donato RM, Marino B.
Cardiac defects and results of cardiac surgery in 22q11.2 deletion syndrome.
Dev Disabil Res Rev. 2008;14(1):35-42. PubMed abstract

Choi JH, Shin YL, Kim GH, Seo EJ, Kim Y, Park IS, Yoo HW.
Endocrine manifestations of chromosome 22q11.2 microdeletion syndrome.
Horm Res. 2005;63(6):294-9. PubMed abstract

Driscoll DA.
Prenatal diagnosis of the 22q11.2 deletion syndrome.
Genet Med. 2001;3(1):14-8. PubMed abstract

Fine SE, Weissman A, Gerdes M, Pinto-Martin J, Zackai EH, McDonald-McGinn DM, Emanuel BS.
Autism spectrum disorders and symptoms in children with molecularly confirmed 22q11.2 deletion syndrome.
J Autism Dev Disord. 2005;35(4):461-70. PubMed abstract

Gerkes EH, Hordijk R, Dijkhuizen T, Sival DA, Meiners LC, Sikkema-Raddatz B, van Ravenswaaij-Arts CM.
Bilateral polymicrogyria as the indicative feature in a child with a 22q11.2 deletion.
Eur J Med Genet. 2010;53(5):344-6. PubMed abstract

Goldmuntz E.
DiGeorge syndrome: new insights.
Clin Perinatol. 2005;32(4):963-78, ix-x. PubMed abstract

Hiéronimus S, Bec-Roche M, Pedeutour F, Lambert JC, Wagner-Malher K, Mas JC, Sadoul JL, Fénichel P.
The spectrum of parathyroid gland dysfunction associated with the microdeletion 22q11.
Eur J Endocrinol. 2006;155(1):47-52. PubMed abstract

Jatana V, Gillis J, Webster BH, Adès LC.
Deletion 22q11.2 syndrome--implications for the intensive care physician.
Pediatr Crit Care Med. 2007;8(5):459-63; quiz 464. PubMed abstract

McDonald-McGinn DM, Sullivan KE.
Chromosome 22q11.2 deletion syndrome (DiGeorge syndrome/velocardiofacial syndrome).
Medicine (Baltimore). 2011;90(1):1-18. PubMed abstract

McDonald-McGinn DM, Tonnesen MK, Laufer-Cahana A, Finucane B, Driscoll DA, Emanuel BS, Zackai EH.
Phenotype of the 22q11.2 deletion in individuals identified through an affected relative: cast a wide FISHing net!.
Genet Med. 2001;3(1):23-9. PubMed abstract

Pereira E, Marion R.
Chromosome 22q11.2 deletion syndrome.
Pediatr Rev. 2015;36(6):270-2; discussion 272. PubMed abstract / Full Text

Perez EE, Bokszczanin A, McDonald-McGinn D, Zackai EH, Sullivan KE.
Safety of live viral vaccines in patients with chromosome 22q11.2 deletion syndrome (DiGeorge syndrome/velocardiofacial syndrome).
Pediatrics. 2003;112(4):e325. PubMed abstract / Full Text
Live virus vaccination is likely safe in children with 22q11.2 deletion, though caution is warranted, especially in those with severe immuno-compromise.

Robin NH, Taylor CJ, McDonald-McGinn DM, Zackai EH, Bingham P, Collins KJ, Earl D, Gill D, Granata T, Guerrini R, Katz N, Kimonis V, Lin JP, Lynch DR, Mohammed SN, Massey RF, McDonald M, Rogers RC, Splitt M, Stevens CA, Tischkowitz MD, Stoodley N, Leventer RJ, Pilz DT, Dobyns WB.
Polymicrogyria and deletion 22q11.2 syndrome: window to the etiology of a common cortical malformation.
Am J Med Genet A. 2006;140(22):2416-25. PubMed abstract

Schneider M, Debbané M, Bassett AS, Chow EW, Fung WL, van den Bree M, Owen M, Murphy KC, Niarchou M, Kates WR, Antshel KM, Fremont W, McDonald-McGinn DM, Gur RE, Zackai EH, Vorstman J, Duijff SN, Klaassen PW, Swillen A, Gothelf D, Green T, Weizman A, Van Amelsvoort T, Evers L, Boot E, Shashi V, Hooper SR, Bearden CE, Jalbrzikowski M, Armando M, Vicari S, Murphy DG, Ousley O, Campbell LE, Simon TJ, Eliez S.
Psychiatric disorders from childhood to adulthood in 22q11.2 deletion syndrome: results from the International Consortium on Brain and Behavior in 22q11.2 Deletion Syndrome.
Am J Psychiatry. 2014;171(6):627-39. PubMed abstract / Full Text

Shooner KA, Rope AF, Hopkin RJ, Andelfinger GU, Benson DW.
Genetic analyses in two extended families with deletion 22q11 syndrome: importance of extracardiac manifestations.
J Pediatr. 2005;146(3):382-7. PubMed abstract

Shprintzen RJ.
Velo-cardio-facial syndrome: 30 Years of study.
Dev Disabil Res Rev. 2008;14(1):3-10. PubMed abstract / Full Text