A patient with 22q11.2 deletion and Opitz syndrome-like phenotype has the same deletion as velocardiofacial patients

Five patients were previously described with the Opitz (GBBB) syndrome (OMIM 145410) phenotype and 22q11.2 deletion determined by FISH but the precise limits of their deletions have not been determined. Since one locus for Opitz syndrome maps to 22q11.2 and chromosomal arrangements are frequently complex and could inactivate such a locus, we performed high-resolution array-based comparative genomic hybridization (CGH) on a new Opitz syndrome-like phenotype patient with a 22q11.2 deletion. He shares the same deletion as patients with velocardiofacial and DiGeorge syndrome.     

Bilateral polymicrogyria as the indicative feature in a child with a 22q11.2 deletion

Polymicrogyria (PMG) is a brain malformation due to abnormal cortical organisation. It is a heterogeneous disorder associated with 22q11.2 deletion syndrome (also known as velocardiofacial (VCF) syndrome) amongst others. Since this association was first recognised in 1996, over 30 patients with PMG and 22q11.2 deletion have been described. In 22q11.2 deletion syndrome, PMG is mainly located in the perisylvian areas; it frequently has an asymmetrical presentation with a striking predisposition for the right hemisphere. Neurological features of perisylvian PMG include developmental delay/mental retardation, seizures, microcephaly, spasticity and oromotor dysfunction. Thus in children diagnosed with 22q11.2 deletion syndrome, a finding of PMG has important prognostic value. We present a seven-month old boy with microcephaly, short stature and developmental delay. A cerebral MRI showed slightly enlarged ventricles and symmetrical perisylvian polymicrogyria. A 22q11.2 deletion was revealed by array-based comparative genomic hybridization. Remarkably the boy had no other manifestations of VCF syndrome. Paediatricians, child neurologists and clinical geneticists should be aware that the presence of PMG (especially in the perisylvian areas) needs investigating for 22q11.2 deletion, even if other more common VCF syndrome features are absent.     

Familial DiGeorge/velocardiofacial syndrome with deletions of chromosome area22q11.2: Report of five families with a review of the literature

The DiGeorge (DG), velocardiofacial (VCF), and conotruncal anomaly-face (CTAF) syndromes were originally described as distinct disorders, although overlapping phenotypes have been recognized. It is now clear that all three syndromes result from apparently similar or identical 22q11.2 deletions, suggesting that they represent phenotypic variability of a single genetic syndrome. We report on 12 individuals in five families with del(22)(q11.2) by fluorescent in situ hybridization, and define the frequency of phenotypic abnormalities in those cases and in 70 individuals from 27 del(22)(q11.2) families from the literature. Common manifestations include mental impairment (97%), abnormal face (93%), cardiac malformations (68%), thymic (64%) and parathyroid (63%) abnormalities, and cleft palate or velopharyngeal insufficiency (48%). Familial DG, VCF, and CTAF syndromes due to del(22)(q11.2) show significant inter- and intra-familial clinical variability consistent with the hypothesis that a single gene or group of tightly linked genes is the common cause of these syndromes. Up to 25% of 22q deletions are inherited, indicating that parents of affected children warrant molecular cytogenetic evaluation. We propose use of the compound term “DiGeorge/velocardiofacial (DG/VCF) syndrome” in referring to this condition, as it calls attention to the phenotypic spectrum using historically familiar names. © 1996 Wiley-Liss, Inc.     

Size of 22q deletions in four previously reported patients with conotruncal anomaly face syndrome

Conotruncal anomaly face syndrome (CTAFS) was distinguished from velo-cardio-facial syndrome (VCFS) in a bind study, yet shared the finding of 22q11.2 deletions. This work has been extended to show that the 22q11.2 deletions in CTAFS greatly overlap those found in VCFS and many DiGeorge patients. The reason for dissimilar phenotypes with apparently similar 22q11.2 deletions is not yet known.     

The morphogenesis of down syndrome: Progress in clinical and biological research. Vol. 373. Charles J. Epstein (Ed.). Wiley-Liss,New York, 1991. pp. xvi + 337. Indexed. $105.00

We describe a patient who had craniofacial and genitourinary abnormalities, swallowing difficulties, esophageal dysfunction, hypotonia and moderate developmental delay, and who also had a terminal deletion of chromosome 13 (q32.3qter). This MCA pattern strongly suggests the Opitz GBBB syndrome. The deletion of chromosome 13 was interpreted as terminal with a breakpoint at 13q32.3. Coagulation factors VII and X located in 13q34, were markedly reduced in the propositus. Although there is some clinical overlap between patients with terminal deletion of 13q and those with the Opitz GBBB syndrome, our patient manifests a whole pattern of abnormalities characteristic of the latter disorder. The concurrence of the Opitz GBBB syndrome and the chromosome abnormality in our patient could be due to chance or, be becuase a gene for the Opitz GBBB syndrome is located at the tip of 13q. © 1995 Wiley-Liss, Inc.     

Comparative study of three diagnostic approaches (FISH, STRs and MLPA) in 30 patients with 22q11.2 deletion syndrome

The 22q11.2 deletion syndrome is commonly diagnosed using fluorescence in situ hybridization (FISH) with commercial probes. The chromosomal breakpoints and deletion size are subsequently characterized by short tandem repeat (STR) segregation tests or by further FISH probes. Recently, a multiplex ligation-dependent probe amplification (MLPA) single tube assay was developed to detect deletions of the 22q11.2 region and other chromosomal regions associated with DiGeorge/velocardiofacial syndrome. We have compared the results of these three techniques in a group of 30 patients affected with 22q11.2 deletion syndrome. MLPA correctly called all patients who had been previously diagnosed by FISH. The MLPA results were concordant in all patients with the STR analysis in respect to deletion size. Furthermore, this novel technique resolved seven cases that were undetermined by STR analysis. These results confirm the efficiency of MLPA as a rapid, reliable, economical, high-throughput method for the diagnosis of 22q11.2 deletion syndrome.     

Microdeletion 22q11 and oesophageal atresia

Oesophageal atresia (OA) is a congenital defect associated with additional malformations in 30-70% of the cases. In particular, OA is a component of the VACTERL association. Since some major features of the VACTERL association, including conotruncal heart defect, radial aplasia, and anal atresia, have been found in patients with microdeletion 22q11.2 (del(22q11.2)), we have screened for del(22q11.2) by fluorescent in situ hybridisation (FISH) in 15 syndromic patients with OA. Del(22q11.2) was detected in one of them, presenting with OA, tetralogy of Fallot, anal atresia, neonatal hypocalcaemia, and subtle facial anomalies resembling those of velocardiofacial syndrome. The occurrence of del(22q11.2) in our series of patients with OA is low (1/15), but this chromosomal anomaly should be included among causative factors of malformation complexes with OA. In addition, clinical variability of del(22q11.2) syndrome is further corroborated with inclusion of OA in the list of the findings associated with the deletion.     

Expanding the fetal phenotype: Prenatal sonographic findings and perinatal outcomes in a cohort of patients with a confirmed 22q11.2 deletion syndrome

22q deletion syndrome (22q11.2DS) is most often correlated prenatally with congenital heart disease and or cleft palate. The extracardiac fetal phenotype associated with 22q11.2DS is not well described. We sought to review both the fetal cardiac and extracardiac findings associated with a cohort of cases ascertained prenatally, confirmed or suspected to have 22q11.2DS, born and cared for in one center. A retrospective chart review was performed on a total of 42 cases with confirmed 22q11.2DS to obtain prenatal findings, perinatal outcomes and diagnostic confirmation. The diagnosis was confirmed prenatally in 67% (28/42) and postnatally in 33% (14/42). The majority (81%) were associated with the standard LCR22A‐LCR22D deletion. 95% (40/42) of fetuses were prenatally diagnosed with congenital heart disease. Extracardiac findings were noted in 90% (38/42) of cases. Additional findings involved the central nervous system (38%), gastrointestinal (14%), genitourinary (16.6%), pulmonary (7%), skeletal (19%), facial dysmorphism (21%), small/hypoplastic thymus (26%), and polyhydramnios (30%). One patient was diagnosed prenatally with a bilateral cleft lip and cleft palate. No fetus was diagnosed with intrauterine growth restriction. The average gestational age at delivery was 38 weeks and average birth weight was 3,105 grams. Sixty‐two percentage were delivered vaginally and there were no fetal demises. A diagnosis of 22q11.2 deletion syndrome should be considered in all cases of prenatally diagnosed congenital heart disease, particularly when it is not isolated. Microarray is warranted in all cases of structural abnormalities diagnosed prenatally. Prenatal diagnosis of 22q11.2 syndrome can be used to counsel expectant parents regarding pregnancy outcome and guide neonatal management.     

Detailed analysis of 22q11.2 with a high density MLPA probe set

The presence of chromosome-specific low-copy repeats (LCRs) predisposes chromosome 22 to deletions and duplications. The current diagnostic procedure for detecting aberrations at 22q11.2 is chromosomal analysis coupled with fluorescence in situ hybridization (FISH) or PCR-based multiplex ligation dependent probe amplification (MLPA). However, there are copy number variations (CNVs) in 22q11.2 that are only detected by high-resolution platforms such as array comparative genomic hybridization (aCGH). We report on development of a high-definition MLPA (MLPA-HD) 22q11 kit that detects copy number changes at 37 loci on the long arm of chromosome 22. These include the 3-Mb region commonly deleted in DiGeorge/velocardiofacial syndrome (DGS/VCFS), the cat eye syndrome (CES) region, and more distal regions in 22q11 that have recently been shown to be deleted. We have used this MLPA-HD probe set to analyze 363 previously well-characterized samples with a variety of different rearrangements at 22q11 and demonstrate that it can detect copy number alterations with high sensitivity and specificity. In addition to detection of the common recurrent deletions associated with DGS/VCFS, variant and novel chromosome 22 aberrations have been detected. These include duplications within as well as deletions distal to this region. Further, the MLPA-HD detects deletion endpoint differences between patients with the common 3-Mb deletion. The MLPA-HD kit is proposed as a cost effective alternative to the currently available detection methods for individuals with features of the 22q11 aberrations. In patients with the relevant phenotypic characteristics, this MLPA-HD probe set could replace FISH for the clinical diagnosis of 22q11.2 deletions and duplications.     

Brain anomalies in velo-cardio-facial syndrome

Magnetic resonance imaging of the brain in 11 consecutively referred patients with velo-cardio-facial syndrome (VCF) showed anomalies in nine cases including small vermis, cysts adjacent to the frontal borns, and small posterior fossal. Focal signal hyperintensities in the white matter on long TR images were also noted. The nine patients showed a variety of behavioral abnormalities including mild developmental delay, learning disabilities, and characteristic personality traits typical of this common multiple anomaly syndrome which has been related to a microdeletion at 22q11. Analysis of the behavioral findings showed no specific pattern related to the brain anomalies, and the patients with VCF who did not have detectable brain lesions also had behavioral abnormalities consistent with VCF. The significance of the lesions is not yet known, but the high prevalence of anomalies in this sample suggests that structural brain abnormalities are probably common in VCF. © 1994 Wiley-Liss, Inc.     

Craniofacial dysmorphology in 22q11.2 deletion syndrome by 3D laser surface imaging and geometric morphometrics: Illuminating the developmental relationship to risk for psychosis

Persons with 22q11.2 deletion syndrome (22q11.2DS) are characterized inter alia by facial dysmorphology and greatly increased risk for psychotic illness. Recent studies indicate facial dysmorphology in adults with schizophrenia. This study evaluates the extent to which the facial dysmorphology of 22q11.2DS is similar to or different from that evident in schizophrenia. Twenty‐one 22q11.2DS‐sibling control pairs were assessed using 3D laser surface imaging. Geometric morphometrics was applied to 30 anatomical landmarks, 480 geometrically homologous semi‐landmarks on curves and 1720 semi‐landmarks interpolated on each 3D facial surface. Principal component (PC) analysis of overall shape space indicated PC2 to strongly distinguish 22q11.2DS from controls. Visualization of PC2 indicated 22q11.2DS and schizophrenia to be similar in terms of overall widening of the upper face, lateral displacement of the eyes/orbits, prominence of the cheeks, narrowing of the lower face, narrowing of nasal prominences and posterior displacement of the chin; they differed in terms of facial length (increased in 22q11.2DS, decreased in schizophrenia), mid‐face and nasal prominences (displaced upwards and outwards in 22q11.2DS, less prominent in schizophrenia); lips (more prominent in 22q11.2DS; less prominent in schizophrenia) and mouth (open mouth posture in 22q11.2DS; closed mouth posture in schizophrenia). These findings directly implicate dysmorphogenesis in a cerebral‐craniofacial domain that is common to 22q11.2DS and schizophrenia and which may repay further clinical and genetic interrogation in relation to the developmental origins of psychotic illness. © 2015 The Authors. American Journal of Medical Genetics Part A Published by Wiley Periodicals, Inc.     

Laryngeal atresia type III (glottic web) with 22q11.2 microdeletion: Report of three patients

The clinical manifestations of patients with a 22q11.2 deletion are highly variable and mainly include developmental defects of structures derived from the third and fourth pharyngeal pouches. Laryngeal atresia has occasionally been reported in DiGeorge syndrome as well as in velo-cardio-facial syndrome. We observed three patients with type III laryngeal atresia (glottic web) and 22q11.2 microdeletion. One patient showed a “classical” 22q11.2 deletion phenotype with clinical overlap with DiGeorge and velo-cardio-facial syndromes. However, the pattern of congenital anomalies of the two others was less specific, heart defects and minor anomalies being the only outstanding clinical manifestations suspicious for monosomy 22q11.2. Our findings suggest that laryngeal atresia represents an additional malformation which should prompt investigation of 22q11.2 deletion, especially in combination with congenital heart defects. Am. J. Med. Genet. 70:130–133, 1997. © 1997 Wiley-Liss, Inc.     

Adverse effects of antipsychotic medication in patients with 22q11.2 deletion syndrome: A systematic review

The 22q11.2 deletion syndrome (22q11.2DS) is a multisystem condition and the most prevalent microdeletion syndrome in humans. Approximately 25% of individuals with 22q11.2DS receive antipsychotic treatment. To assess whether patients with 22q11.2DS are vulnerable to adverse effects of antipsychotic medication, we carried out a literature review. A systematic search strategy was performed using PubMed (Medline), Embase, PsychInfo, and Cochrane Database of Systematic Reviews. Publications describing adverse effects of antipsychotic medication in patients with 22q11.2DS were included in the review and assessed for their methodological quality. A total of 11 publications reporting on eight trials, cross‐sectional or cohort studies, and 30 case reports were included. The most commonly reported adverse effects can be classified into the following categories: movement disorders, weight gain, seizures, cardiac side effects, and cytopenias. Many of these symptoms are manifestations of 22q11.2DS, also in the absence of antipsychotic medication. Based on the reviewed literature, a causal relation between antipsychotic medication and the reported adverse effects could not be established in the majority of cases. Randomized clinical trials are needed to make firm conclusions regarding risk of adverse effects of antipsychotics in patients with 22q11.2DS.     

Vestibular dysfunction is a manifestation of 22q11.2 deletion syndrome

The 22q11.2 deletion syndrome (22q11.2DS) is the second most common cause of developmental delay after Down syndrome. Impaired cognitive development is highly prevalent, but also motor abnormalities such as hypotonia and delays in achieving motor milestones are described. Instability is frequently detected in children, adolescents, and adults and is mostly attributed to their limited motor performance. Until now, vestibular function has not been investigated in these patients, despite the growing evidence that they often have inner ear malformations. The aim of this prospective study was to identify the presence and character of vestibular dysfunction in 22q11.2DS. We investigated 23 subjects with proven 22q11.2DS, older than the age of 12. We performed caloric testing and pendular rotation chair tests with videonystagmography, cervical vestibular‐evoked myogenic potential (c‐VEMP)‐testing, and posturography. Additional otoscopy and audiometry were performed on all subjects. We found a unilateral caloric hypofunction in 55% of patients, a certain absent c‐VEMP response in 15% of ears, an inconclusive c‐VEMP response in 33% of ears, and abnormal posturography in 68% of patients, of whom 42% displayed a typical vestibular pattern. Remarkably, 90% revealed uni‐ or bilateral weak caloric responses, independent of caloric symmetry. Vestibular dysfunction is frequent in subjects with 22q11.2DS. This knowledge should be taken into account when assessing motor performance in these patients. Additional larger studies are needed to determine whether this dysfunction implicates a therapeutic potential.     

Wilms tumor in a patient with 22q11.2 microdeletion

22q11.2 deletion syndrome is the most common microdeletion syndrome. Wilms tumor is one of the most common solid tumors in childhood yet 22q11.2 deletion and Wilms tumor only once have been reported in the same patient. Here we describe a young patient with subtle clinical findings suggestive of 22q11.2 at the time of diagnosis who subsequently developed Wilms tumor. We assert the importance of a low threshold for screening for 22q11.2 deletion and the associated phenotypes and maintaining vigilance in screening for common primary malignancies in patients with known 22q11.2 deletion.     

Nasal dimple as part of the 22q11.2 deletion syndrome

The phenotype of the 22q11.2 microdeletion syndrome is quite variable. We describe 2 patients with a 22q11.2 deletion and a dimpled nasal tip, which, we suggest can be the extreme of the broad or bulbous nose commonly found in the 22q11.2 deletion syndrome, and should not be confused with the more severe nasal abnormalities seen in frontonasal dysplasia. Am. J. Med. Genet. 69:290–292, 1997. © 1997 Wiley-Liss, Inc.     

Spectrum of clinical variability in familial deletion 22q11.2: from full manifestation to extremely mild clinical anomalies

The 22q11.2 deletion (del22q11.2) syndrome is a genetic condition with wide interfamilial and intrafamilial variability in clinical expression. The aim of the present study was to review the prevalence of parental transmission in our series of patients with del22q11.2, and to analyse clinical findings of the affected parents. Parental transmission of del22q11.2 in our series was 17.2% (15/87), with a preferential maternal transmission (10/15). One or more major features of del22q11.2 were found in all deleted parents, but one of the mothers showed extremely mild clinical anomalies. The present data demonstrate that it should be current policy to test both parents of patients with del22q11.2, irrespective of the parental phenotype, in view of the fact that extremely mild clinical features can be detected in parents of deleted patients. This would provide accurate genetic counselling to del22q11.2 families, as relatively asymptomatic parents must be advised of the 50% risk of transmitting the deletion in a subsequent pregnancy. Various genetic and non-genetic factors, including modifier genes at separate loci, mosaicism, unstable mutations, allelic variations at the haploid locus, chance and environmental interaction, can be hypothesized to be involved in variable clinical expression, even in the same family.     

Updated clinical practice recommendations for managing adults with 22q11.2 deletion syndrome

This review aimed to update the clinical practice guidelines for managing adults with 22q11.2 deletion syndrome (22q11.2DS). The 22q11.2 Society recruited expert clinicians worldwide to revise the original clinical practice guidelines for adults in a stepwise process according to best practices: (1) a systematic literature search (1992-2021), (2) study selection and synthesis by clinical experts from 8 countries, covering 24 subspecialties, and (3) formulation of consensus recommendations based on the literature and further shaped by patient advocate survey results. Of 2441 22q11.2DS-relevant publications initially identified, 2344 received full-text review, with 2318 meeting inclusion criteria (clinical care relevance to 22q11.2DS) including 894 with potential relevance to adults. The evidence base remains limited. Thus multidisciplinary recommendations represent statements of current best practice for this evolving field, informed by the available literature. These recommendations provide guidance for the recognition, evaluation, surveillance, and management of the many emerging and chronic 22q11.2DS-associated multisystem morbidities relevant to adults. The recommendations also address key genetic counseling and psychosocial considerations for the increasing numbers of adults with this complex condition.     

22q11.2 deletions in a series of patients with non-selective congenital heart defects: incidence, type of defects and parental origin

Previous studies have indicated a wide spectrum of incidences of 22q11.2 deletions in isolated and syndromic (sporadic or familial) cases of conotruncal heart defects, whereby the detection rate of the deletion varied from 65% in one study to 0 in another. We analysed 110 patients with non-selective syndromic or isolated non-familial congenital heart malformations by fluorescence in situ hybridization (FISH) using the D22S75 DiGeorge chromosome (DGS) region probe. A 22q11.2 microdeletion has been detected in 9/51 (17.6%) syndromic patients. Five were of maternal origin and four of paternal origin. None of the 59 patients with isolated congenital cardiac defect had a 22q11.2 deletion. We compared the cardiac anomalies of our patients with a 22q11.2 deletion with those of previously published series and we describe types of congenital heart defects which appear to be often associated with a 22q11.2 deletion. The ability to detect such types of heart defects and to provide an early diagnosis of 22q11.2 deletion is particularly relevant in very young infants, who often show only very mild expression of the otherwise well-characterized phenotypes of the DiGeorge/velo–cardio–facial syndrome (DG/VCFS).