Communication issues in 22q11.2 deletion syndrome: children at risk

PURPOSE

The purpose of this investigation is to describe the communication profile of children with the 22q11.2 deletion syndrome from infancy through school age and to examine the influence of other medical aspects, such as palate anomalies, learning disorders, and cardiac defects of the syndrome to communication.

METHODS

Seventy-nine children were examined using standardized tests of speech and language and perceptual measures of resonance and voice.

RESULTS

Results show significant delay in emergence of speech and language milestones with delay/disorder in speech-language processes persisting into the school aged years, including those children diagnosed with nonverbal learning disabilities. Persistent articulation and resonance disorders were also present, presumed to be related in part to palatal anomalies. No correlation was found between cardiac status, learning disorders, palate anomalies and communication disorders.

CONCLUSION

The need for early identification and management of communication skills is crucial in the care of children with the 22q11.2 deletion.

Neuropsychological profile of children and adolescents with the 22q11.2 microdeletion

PURPOSE

Patients with one of the 22q11.2 deletion syndromes provide a unique opportunity to research the interface between genetics and brain-behavior relationships. This study investigates the neuropsychological characteristics and behavioral phenotype of children with this deletion syndrome.

METHODS

We report updated findings from descriptive and nonparametric analyses of neuropsychological data from 80 children with the 22q11.2 deletion.

RESULTS

The subjects showed higher verbal than nonverbal IQ scores, assets in verbal memory, and deficits in the areas of attention, story memory, visuospatial memory, arithmetic performance relative to other areas of achievement, and psychosocial functioning.

CONCLUSION

Children with 22q11.2 deletion syndromes exhibit a behavioral phenotype reflective of nonverbal learning disabilities, concomitant language deficits, and social-emotional concerns.

Communication disorders in the 22Q11.2 microdeletion syndrome

The 22q11.2 microdeletion syndrome is a genetic disorder that is being recognized with increasing frequency. Confirmation of the diagnosis can be made using fluorescence in situ hybridization. Many medical and developmental problems are present in children with this syndrome. Communication disorders are among the most common features of this syndrome and include articulation, language, resonance, and voice problems. The purpose of this paper is to provide a description of the communicative and developmental features in a sample of children with the 22q11.2 microdeletion syndrome seen for evaluation. Because communication and feeding disorders may be presenting features of this syndrome, speech and language pathologists must be familiar with this syndrome and its various characteristics. Awareness of these features and a multidisciplinary approach are necessary for the identification and treatment of the complex communicative and medical problems present in this population.

Submicroscopic deletion in cousins with Prader-Willi syndrome causes a grandmatrilineal inheritance pattern: effects of imprinting

The Prader-Willi syndrome (PWS) critical region on 15q11-q13 is subject to imprinting. PWS becomes apparent when genes on the paternally inherited chromosome are not expressed. Familial PWS is rare. We report on a family in which a male and a female paternal first cousin both have PWS with cytogenetically normal karyotypes. Fluorescence in situ hybridization (FISH) analysis shows a submicroscopic deletion of SNRPN, but not the closely associated loci D15S10, D15S11, D15S63, and GABRB3. The cousins' fathers and two paternal aunts have the same deletion and are clinically normal. The grandmother of the cousins is deceased and not available for study, and their grandfather is not deleted for SNRPN. DNA methylation analysis of D15S63 is consistent with an abnormality of the imprinting center associated with PWS. "Grandmatrilineal" inheritance occurs when a woman with deletion of an imprinted, paternally expressed gene is at risk of having affected grandchildren through her sons. In this case, PWS does not become evident as long as the deletion is passed through the matrilineal line. This represents a unique inheritance pattern due to imprinting.

Chromosome 22-specific low copy repeats and the 22q11.2 deletion syndrome: genomic organization and deletion endpoint analysis

The 22q11.2 deletion syndrome, which includes DiGeorge and velocardiofacial syndromes (DGS/VCFS), is the most common microdeletion syndrome. The majority of deleted patients share a common 3 Mb hemizygous deletion of 22q11.2. The remaining patients include those who have smaller deletions that are nested within the 3 Mb typically deleted region (TDR) and a few with rare deletions that have no overlap with the TDR. The identification of chromosome 22-specific duplicated sequences or low copy repeats (LCRs) near the end-points of the 3 Mb TDR has led to the hypothesis that they mediate deletions of 22q11.2. The entire 3 Mb TDR has been sequenced, permitting detailed investigation of the LCRs and their involvement in the 22q11.2 deletions. Sequence analysis has identified four LCRs within the 3 Mb TDR. Although the LCRs differ in content and organization of shared modules, those modules that are common between them share 97-98% sequence identity with one another. By fluorescence in situ hybridization (FISH) analysis, the end-points of four variant 22q11.2 deletions appear to localize to the LCRs. Pulsed-field gel electrophoresis and Southern hybridization have been used to identify rearranged junction fragments from three variant deletions. Analysis of junction fragments by PCR and sequencing of the PCR products implicate the LCRs directly in the formation of 22q11.2 deletions. The evolutionary origin of the duplications on chromosome 22 has been assessed by FISH analysis of non-human primates. Multiple signals in Old World monkeys suggest that the duplication events may have occurred at least 20-25 million years ago.

Longitudinal analysis of lymphocyte function and numbers in the first year of life in chromosome 22q11.2 deletion syndrome (DiGeorge syndrome/velocardiofacial syndrome)

Chromosome 22q11.2 deletion syndrome is a common syndrome typically consisting of variable cardiac defects, hypoparathyroidism, developmental delay, and immunodeficiency. The hemizygous deletion has variable effects on the immune system even within the same kindred, and the extent of the immunodeficiency is difficult to predict. Some patients have shown improvement over time; however, this is the first prospective longitudinal study of the dynamic nature of the immunodeficiency. Nineteen patients were studied prospectively between 1994 and 1997. The results of the newborn immunologic studies in the chromosome 22q11.2 deletion group were significantly different from those of a group of newborns with cardiac disease due to other causes. Peripheral blood T-cell numbers were decreased in the chromosome 22q11.2 deletion group, although T-cell function was largely preserved. The group as a whole demonstrated few changes in the first year of life, but a subset of patients with markedly diminished T-cell numbers did demonstrate improvement. Therefore, improvement in peripheral blood T-cell counts is variable in chromosome 22q11.2 deletion syndrome. The patients with the lowest T-cell counts improved the most in the first year of life.

Cognitive and behavior profile of preschool children with chromosome 22q11.2 deletion

A microscopic deletion of chromosome 22q11.2 has been identified in most patients with the DiGeorge, velocardiofacial syndrome, conotruncal anomaly face syndrome, and in some patients with isolated conotruncal cardiac anomalies. This study presents the neurodevelopmental outcome, including cognitive development, language development, speech, neuromuscular development, and behavioral characteristics of 40 preschool children (ages 13 to 63 months) who have been diagnosed with the 22q11.2 deletion. The impact of cardiac disease, cardiac surgery, and the palatal anomalies on this population was also studied. In the preschool years, children with a 22q11.2 deletion are most commonly found to be developmentally delayed, have mild hypotonia, and language and speech delays. The more significantly delayed children are at high risk to be subsequently diagnosed with mild or moderate mental retardation. The global delays and the variations in intelligence found are directly associated with the 22q11.2 deletion and are not explained by physical anomalies such as palatal defects or cardiac defects, or therapeutic interventions such as cardiac surgery. Our findings demonstrate that there is a pattern of significant speech disorders within this population. All of the children had late onset of verbal speech. Behavioral outcomes included both inhibition and attention disorders. Early intervention services are strongly recommended beginning in infancy to address the delays in gross motor skills, speech and language, and global developmental delays.

The Philadelphia story: the 22q11.2 deletion: report on 250 patients

A submicroscopic deletion of chromosome 22q11.2 has been identified in the majority of patients with the DiGeorge, velocardiofacial, and conotruncal anomaly face syndromes, and in some patients with the Opitz G/BBB and Cayler cardiofacial syndromes. We have been involved in the analysis of DiGeorge syndrome and related diagnoses since 1982 and have evaluated a large number of patients with the deletion. We describe our cohort of 250 patients whose clinical findings help to define the extremely variable phenotype associated with the 22q11.2 deletion and may assist clinicians in providing genetic counseling and guidelines for clinical management based on these findings.

Aphallia as part of urorectal septum malformation sequence in an infant of a diabetic mother

A male patient with aphallia, anal stenosis, tetralogy of Fallot, multiple vertebral anomalies including sacral agenesis and central nervous system (CNS) malformations was born after a pregnancy complicated by poorly controlled maternal diabetes. Aphallia is an extremely rare abnormality and can be part of the urorectal septum malformation sequence (URSMS). While aphallia has not been reported in infants of diabetic mothers, urogenital malformations are known to occur with increased frequency. Two female products of pregnancies complicated by diabetes presented with multiple malformations including anal atresia and recto-vaginal fistula consistent with the diagnosis of URSMS. The three patients share CNS, cardiac, and vertebral anomalies, abnormalities secondary to abnormal blastogenesis and characteristic of diabetic embryopathy. URSMS is also caused by abnormal blastogenesis. Therefore, this particular malformation should be viewed in the context of the multiple blastogenetic abnormalities in the cases reported here. The overlap of findings of URSMS in our cases with other abnormalities of blastogenesis, such as VATER association or sacral agenesis is not surprising, as these associations are known to lack clear diagnostic boundaries.

Psychoeducational profile of the 22q11.2 microdeletion: A complex pattern

OBJECTIVES

To examine the psychoeducational profile associated with the chromosome 22q11.2 microdeletion (DiGeorge/velocardiofacial syndrome).

STUDY DESIGN

Thirty-three patients (aged 6 to 27 years) with a 22q11.2 microdeletion underwent psychoeducational testing as part of a comprehensive evaluation. Nonparametric statistics were used to compare verbal and performance IQ, academic achievement scores, and receptive versus expressive language scores. Post hoc comparisons were made of IQ subtest scores and of language versus verbal IQ.

RESULTS

Full-scale IQ ranged from the normal to the moderately retarded range. Mean verbal IQ was significantly higher than mean performance IQ. In a similar manner, mean reading and spelling scores were superior to the mean mathematics score, although achievement scores typically were in the range of verbal IQ. In addition, many children showed clinically significant language impairments, with mean language scores lower than mean verbal IQ.

CONCLUSIONS

The IQ and academic profiles are reminiscent of a "nonverbal learning disability," although achievement was not discrepant from IQ. The coincidence of language impairment with a relative strength in reading belies a unique neuropsychologic profile. Educational programming for these children must address both verbal and nonverbal deficits.

De novo alu-element insertions in FGFR2 identify a distinct pathological basis for Apert syndrome

Apert syndrome, one of five craniosynostosis syndromes caused by allelic mutations of fibroblast growth-factor receptor 2 (FGFR2), is characterized by symmetrical bony syndactyly of the hands and feet. We have analyzed 260 unrelated patients, all but 2 of whom have missense mutations in exon 7, which affect a dipeptide in the linker region between the second and third immunoglobulin-like domains. Hence, the molecular mechanism of Apert syndrome is exquisitely specific. FGFR2 mutations in the remaining two patients are distinct in position and nature. Surprisingly, each patient harbors an Alu-element insertion of approximately 360 bp, in one case just upstream of exon 9 and in the other case within exon 9 itself. The insertions are likely to be pathological, because they have arisen de novo; in both cases this occurred on the paternal chromosome. FGFR2 is present in alternatively spliced isoforms characterized by either the IIIb (exon 8) or IIIc (exon 9) domains (keratinocyte growth-factor receptor [KGFR] and bacterially expressed kinase, respectively), which are differentially expressed in mouse limbs on embryonic day 13. Splicing of exon 9 was examined in RNA extracted from fibroblasts and keratinocytes from one patient with an Alu insertion and two patients with Pfeiffer syndrome who had nucleotide substitutions of the exon 9 acceptor splice site. Ectopic expression of KGFR in the fibroblast lines correlated with the severity of limb abnormalities. This provides the first genetic evidence that signaling through KGFR causes syndactyly in Apert syndrome.

TWIST gene mutation in a patient with radial aplasia and craniosynostosis: further evidence for heterogeneity of Baller-Gerold syndrome

The term Baller-Gerold syndrome was coined by Cohen [1979: Birth Defects 15(5B): 13-63] to designate the phenotype of craniosynostosis and radial aplasia. It is thought to be a rare autosomal recessive condition, which, in some patients, presents with additional abnormalities, such as polymicrogyria, mental retardation or anal atresia. A phenotypic overlap of Baller-Gerold and Roberts-SC phocomelia syndrome was noted when a patient with bicoronal synostosis and bilateral radial hypoplasia was found to have premature centromere separation, a finding characteristic of Roberts syndrome [Huson et al.,1990: J Med Genet 27:371-375]. Other cases of presumed Baller-Gerold syndrome were rediagnosed as Fanconi pancytopenia, Rothmund-Thomson syndrome or VACTERL association. These reports led to a narrowed redefinition of Baller-Gerold syndrome based on the exclusion of cytogenetic and hematopoetic abnormalities and the absence of additional malformations in patients with craniosynostosis and preaxial upper limb abnormalities. Here we report on a patient with unilateral radial aplasia and bicoronal synostosis without additional malformations and without chromosome breakage, who fits this narrow definition of Baller-Gerold syndrome. We identified a novel TWIST gene mutation in this patient, a Glu181Stop mutation predicting a premature termination of the protein carboxy-terminal to the helix 2 domain. This report provides further evidence that Baller-Gerold is of heterogeneous cause, and a thorough evaluation is indicated to identify a possibly more specific diagnosis, including Saethre-Chotzen syndrome. This differential diagnosis is of particular importance, as it is an autosomal dominant trait. Therefore, the recurrence risk for parents of an affected child can be 50% if one parent carries the mutation, as opposed to the 25% recurrence risk for autosomal recessive inheritance. Offspring of the affected patient also have a 50% risk to inherit the mutation, while the risk to bear an affected offspring for an autosomal recessive trait is very low.

Fibroblast growth factor homologous factor 2 (FHF2): gene structure, expression and mapping to the Börjeson-Forssman-Lehmann syndrome region in Xq26 delineated by a duplication breakpoint in a BFLS-like patient

Börjeson-Forssman-Lehmann syndrome (BFLS) is a syndromal X-linked mental retardation, which maps by linkage to the q26 region of the human X chromosome. We have identified a male patient with BFLS-like features and a duplication, 46,Y,dup(X)(q26q28), inherited from his phenotypically normal mother. Fluorescence in situ hybridisation using yeast artificial chromosome clones from Xq26 localised the duplication breakpoint to an approximately 400-kb interval in the Xq26.3 region between DXS155 and DXS294/DXS730. Database searches and analysis of available genomic DNA sequence from the region revealed the presence of the fibroblast growth factor homologous factor gene, FHF2, within the duplication breakpoint interval. The gene structure of FHF2 was determined and two new exons were identified, including a new 5' end exon, 1B. FHF2 is a large gene extending over approximately 200 kb in Xq26.3 and is composed of at least seven exons. It shows tissue-specific alternative splicing and alternative transcription starts. Northern blot hybridisation showed highest expression in brain and skeletal muscle. The FHF2 gene localisation and tissue-specific expression pattern suggest it to be a candidate gene for familial cases of the BFLS syndrome and other syndromal and non-specific forms of X-linked mental retardation mapping to the region.

Polymicrogyria in chromosome 22 delection syndrome

We report two children with chromosome 22q11 deletion syndrome who had neuroradiologic evidence of polymicrogyria. The diagnosis of chromosome 22q11 deletion should be considered in individuals with polymicrogyria.

Hemifacial microsomia in a newborn with hypoplastic skin lesions, an eyelid skin tag, and microphthalmia: an unusual presentation of Delleman syndrome

Delleman syndrome (oculocerebrocutaneous syndrome) is characterized by orbital cysts, periorbital skin appendages, and focal cutaneous hypoplasia. We describe a male infant with findings associated with this condition, including an eyelid appendage, discrete hypoplastic skin lesions, unilateral microphthalmia, and hydrocephalus. In addition, he had striking unilateral mandibular hypoplasia and microtia, features often present in the oculoauriculovertebral (OAV) spectrum. However, hypoplastic skin lesions and eyelid appendages are not features of the OAV spectrum. The marked degree of hemifacial microsomia present in this child has not been previously noted in Delleman syndrome. Two patients with Delleman syndrome have been previously described who have features typically present in the OAV spectrum. This case demonstrates that characteristics of both Delleman syndrome and the OAV spectrum may be present in one individual.

Frequency of 22q11 deletions in patients with conotruncal defects

OBJECTIVES

This study was designed to determine the frequency of 22q11 deletions in a large, prospectively ascertained sample of patients with conotruncal defects and to evaluate the deletion frequency when additional cardiac findings are also considered.

BACKGROUND

Chromosome 22q11 deletions are present in the majority of patients with DiGeorge, velocardiofacial and conotruncal anomaly face syndromes in which conotruncal defects are a cardinal feature. Previous studies suggest that a substantial number of patients with congenital heart disease have a 22q11 deletion.

METHODS

Two hundred fifty-one patients with conotruncal defects were prospectively enrolled into the study and screened for the presence of a 22q11 deletion.

RESULTS

Deletions were found in 50.0% with interrupted aortic arch (IAA), 34.5% of patients with truncus arteriosus (TA), and 15.9% with tetralogy of Fallot (TOF). Two of 6 patients with a posterior malalignment type ventricular septal defect (PMVSD) and only 1 of 20 patients with double outlet right ventricle were found to have a 22q11 deletion. None of the 45 patients with transposition of the great arteries had a deletion. The frequency of 22q11 deletions was higher in patients with anomalies of the pulmonary arteries, aortic arch or its major branches as compared to patients with a normal left aortic arch regardless of intracardiac anatomy.

CONCLUSIONS

A substantial proportion of patients with IAA, TA, TOF and PMVSD have a deletion of chromosome 22q11. Deletions are more common in patients with aortic arch or vessel anomalies. These results begin to define guidelines for deletion screening of patients with conotruncal defects.

Phenotype of the fibroblast growth factor receptor 2 Ser351Cys mutation: Pfeiffer syndrome type III

We present a patient with pansynostosis, hydrocephalus, seizures, extreme proptosis with luxation of the eyes out of the lids, apnea and airway obstruction, intestinal non-rotation, and severe developmental delay. His skeletal abnormalities include bilateral elbow ankylosis, radial head dislocation, and unilateral broad and deviated first toe. The phenotype of this patient is consistent with that previously reported in Pfeiffer syndrome type III, but is unusual for the lack of broad thumbs. Our patient most closely resembles the case described by Kerr et al. [1996: Am J Med Genet 66:138-143] as Pfeiffer syndrome type III with normal thumbs. Mutations in the genes for fibroblast growth factor receptors (FGFR) 1 and 2 have previously been seen in patients with Pfeiffer syndrome type I. The mutation identified in our patient, Ser351Cys in FGFR2, represents the first reported cause of Pfeiffer syndrome type III. An identical mutation was described once previously by Pulleyn et al., in a patient whose brief clinical description included cloverleaf skull, significant developmental delay, and normal hands and feet [Eur. J. Hum. Genet. 4: 283-291, 1996]. In our patient, previously performed single-strand conformation polymorphism analysis failed to detect a band shift; the mutation was identified only after independent sequence analysis.

Increased prevalence of immunoglobulin A deficiency in patients with the chromosome 22q11.2 deletion syndrome (DiGeorge syndrome/velocardiofacial syndrome)

We wished to determine the prevalence of immunoglobulin A (IgA) deficiency in patients with the chromosome 22q11.2 deletion syndrome. A total of 32 patients with the chromosome 22q11.2 deletion were examined for IgA deficiency. We report a 13% (n = 4) prevalence of IgA deficiency in patients with this syndrome. The odds ratio of IgA deficiency in this population is 14.20 (P < 0.0001). This confirms the occurrence of significant humoral deficits in this predominantly cellular immunodeficiency.

Growth hormone deficiency in patients with 22q11.2 deletion: expanding the phenotype

The list of findings associated with the 22q11.2 deletion is quite long and varies from patient to patient. The hallmark features include: conoruncal cardiac anomalies, palatal defects, thymic aplasia or hypoplasia, T cell abnormalities, mild facial dysmorphia, and learning disabilities. The 22q11.2 deletion has been seen in association with the DiGeorge sequence, velocardiofacial syndrome (VCFS), conotruncal anomaly face syndrome, isolated conotruncal cardiac anomalies, and some cases of autosomal dominant Optiz G/BBB syndrome. Short stature has been seen in one to two thirds of children reported in the literature with a diagnosis of VCFS, but growth hormone deficiency (GHD) has not been described in conjunction with this diagnosis. We present 4 patients with a 22q11.2 deletion and short stature who were found to have abnormalities in the growth hormone-insulin-like growth factor I axis. All had growth factors less than -2 SD for age and failed provocative growth hormone testing. Two patients were found to have abnormal pituitary anatomy. In our population, the incidence of GHD in 4 or 95 children with 22q11 deletion is significantly greater than the estimated incidence of GHD in the general population. Children with a 22q11.2 deletion appear to be at a greater risk for pituitary abnormalities. Therefore, those children with the 22q11.2 deletion and short stature or poor growth should be evaluated for GHD, as replacement growth hormone therapy may improve their growth velocity and final height prediction.

Identification of a genetic cause for isolated unilateral coronal synostosis: a unique mutation in the fibroblast growth factor receptor 3

To determine whether the autosomal dominant fibroblast growth factor receptor 3 (FGFR3) Pro250Arg mutation causes anterior plagiocephaly, patients with either apparently sporadic unicoronal synostosis (N = 37) or other forms of anterior plagiocephaly (N = 10) were studied for this mutation. Of 37 patients with unicoronal synostosis, 4 tested positive for the Pro250Arg mutation in FGFR3, and 33 were negative for this mutation. In three mutation positive patients with full parental studies, a parent with an extremely mild phenotype was found to carry the same mutation. None of the 6 patients with nonsynostotic plagiocephaly and none of the 4 patients with additional suture synostosis had the FGFR3 mutation. Because it is impossible to predict the FGFR3 Pro250Arg mutation status based on clinical examination alone, all patients with unicoronal synostosis should be tested for it. To assess their recurrence risk, all parents of mutation positive patients should be tested regardless of their clinical findings, because the phenotype can be extremely variable and without craniosynostosis.

Lack of correlation between impaired T cell production, immunodeficiency, and other phenotypic features in chromosome 22q11.2 deletion syndromes

Monosomic deletions of chromosome 22q11.2 are the leading cause of DiGeorge syndrome, velocardiofacial syndrome, and conotruncal anomaly face syndrome. DiGeorge syndrome was originally described as an immunodeficiency disorder secondary to impaired T cell production due to thymic aplasia or hypoplasia; however, the frequency of immunodeficiency in the other clinical syndromes associated with the chromosome 22q11.2 microdeletion has not been previously investigated. This study examines the frequency and severity of impaired T cell production and immunodeficiency in chromosome 22q11.2 deletion syndromes and the relationship of the immunodeficiency to specific phenotypic features. Sixty patients over 6 months of age with the characteristic chromosome 22q11.2 deletion underwent immunologic evaluations. Seventy-seven percent of patients with chromosome 22q11.2 deletions were found to have evidence of immunocompromise. The severity of the immunodeficiency did not correlate with any particular phenotypic feature, nor was it restricted to patients who were categorized as having DiGeorge syndrome. Therefore, impaired T cell production and impaired immunologic function are common in patients with deletions of chromosome 22q11.2. The presence or severity of the immunocompromise cannot be predicted based on other phenotypic features and each child should be individually assessed for immune function.

Heterotaxia in a fetus with campomelia, cervical lymphocele, polysplenia, and multicystic dysplastic kidneys: expanding the phenotype of Cumming syndrome

We report on a fetus with tetramelic campomelia, polysplenia, multicystic dysplastic kidneys, and cervical lymphocele. This condition is similar to the autosomal recessive condition described by Cumming et al. [1986: Am J Med Genet 25:783-790] and is different from campomelic syndrome. In addition, our case had anomalies not previously described in this condition, including abnormal lung lobation with bilateral left bronchial morphology, dextrocardia, total anomalous pulmonary venous return, a left superior vena cava, and a right aortic arch. The pancreas was short, with absence of the body and tail. These anomalies are similar to those found in the polyasplenia spectrum. We suggest that the syndrome reported by Cumming et al. may be expanded to include polysplenia with heterotaxia and that Cumming syndrome may be considered another autosomal recessive condition associated with a laterality defect.

Skeletal anomalies and deformities in patients with deletions of 22q11

Skeletal anomalies in patients with a 22q11.2 deletion are reported infrequently. We report the skeletal findings in 108 patients with a 22q11.2 deletion, of whom 37 (36%) had a skeletal anomaly. Twenty-two patients (20%) had anomalies of the limbs, 7 of the upper limb, including preaxial or postaxial polydactyly. An anomaly of the lower limb was found in 16 patients, including postaxial polydactyly, clubfoot, severely overfolded toes, and 2-3 toe cutaneous syndactyly. Chest films of 63 patients were examined; 30% of them had abnormal findings, most commonly supernumerary ribs (17%) or a "butterfly" vertebral body (11%). Hypoplastic vertebrae, hemivertebrae, and vertebral coronal clefts were also noted. Thus, skeletal anomalies are not uncommon in patients with a 22q11.2 deletion and may occur more frequently than recognized previously.