Functional DNA methylation signatures for autism spectrum disorder genomic risk loci: 16p11.2 deletions and CHD8 variants.

BACKGROUND: Autism spectrum disorder (ASD) is a common and etiologically heterogeneous neurodevelopmental disorder. Although many genetic causes have been identified (> 200 ASD-risk genes), no single gene variant accounts for > 1% of all ASD cases. A role for epigenetic mechanisms in ASD etiology is supported by the fact that many ASD-risk genes function as epigenetic regulators and evidence that epigenetic dysregulation can interrupt normal brain development. Gene-specific DNAm profiles have been shown to assist in the interpretation of variants of unknown significance. Therefore, we investigated the epigenome in patients with ASD or two of the most common genomic variants conferring increased risk for ASD. Genome-wide DNA methylation (DNAm) was assessed using the Illumina Infinium HumanMethylation450 and MethylationEPIC arrays in blood from individuals with ASD of heterogeneous, undefined etiology (n = 52), and individuals with 16p11.2 deletions (16p11.2del, n = 9) or pathogenic variants in the chromatin modifier CHD8 (CHD8+/-, n = 7). RESULTS: DNAm patterns did not clearly distinguish heterogeneous ASD cases from controls. However, the homogeneous genetically-defined 16p11.2del and CHD8+/- subgroups each exhibited unique DNAm signatures that distinguished 16p11.2del or CHD8+/- individuals from each other and from heterogeneous ASD and control groups with high sensitivity and specificity. These signatures also classified additional 16p11.2del (n = 9) and CHD8 (n = 13) variants as pathogenic or benign. Our findings that DNAm alterations in each signature target unique genes in relevant biological pathways including neural development support their functional relevance. Furthermore, genes identified in our CHD8+/- DNAm signature in blood overlapped differentially expressed genes in CHD8+/- human-induced pluripotent cell-derived neurons and cerebral organoids from independent studies. CONCLUSIONS: DNAm signatures can provide clinical utility complementary to next-generation sequencing in the interpretation of variants of unknown significance. Our study constitutes a novel approach for ASD risk-associated molecular classification that elucidates the vital cross-talk between genetics and epigenetics in the etiology of ASD.

Parents' Experience with Pediatric Microarray: Transferrable Lessons in the Era of Genomic Counseling.

Advances in genome-based microarray and sequencing technologies hold tremendous promise for understanding, better-managing and/or preventing disease and disease-related risk. Chromosome microarray technology (array based comparative genomic hybridization [aCGH]) is widely utilized in pediatric care to inform diagnostic etiology and medical management. Less clear is how parents experience and perceive the value of this technology. This study explored parents' experiences with aCGH in the pediatric setting, focusing on how they make meaning of various types of test results. We conducted in-person or telephone-based semi-structured interviews with parents of 21 children who underwent aCGH testing in 2010. Transcripts were coded and analyzed thematically according to the principles of interpretive description. We learned that parents expect genomic tests to be of personal use; their experiences with aCGH results characterize this use as intrinsic in the test's ability to provide a much sought-after answer for their child's condition, and instrumental in its ability to guide care, access to services, and family planning. In addition, parents experience uncertainty regardless of whether aCGH results are of pathogenic, uncertain, or benign significance; this triggers frustration, fear, and hope. Findings reported herein better characterize the notion of personal utility and highlight the pervasive nature of uncertainty in the context of genomic testing. Empiric research that links pre-test counseling content and psychosocial outcomes is warranted to optimize patient care.

NSD1 mutations generate a genome-wide DNA methylation signature.

Sotos syndrome (SS) represents an important human model system for the study of epigenetic regulation; it is an overgrowth/intellectual disability syndrome caused by mutations in a histone methyltransferase, NSD1. As layered epigenetic modifications are often interdependent, we propose that pathogenic NSD1 mutations have a genome-wide impact on the most stable epigenetic mark, DNA methylation (DNAm). By interrogating DNAm in SS patients, we identify a genome-wide, highly significant NSD1(+/-)-specific signature that differentiates pathogenic NSD1 mutations from controls, benign NSD1 variants and the clinically overlapping Weaver syndrome. Validation studies of independent cohorts of SS and controls assigned 100% of these samples correctly. This highly specific and sensitive NSD1(+/-) signature encompasses genes that function in cellular morphogenesis and neuronal differentiation, reflecting cardinal features of the SS phenotype. The identification of SS-specific genome-wide DNAm alterations will facilitate both the elucidation of the molecular pathophysiology of SS and the development of improved diagnostic testing.

Phenotypic spectrum associated with PTCHD1 deletions and truncating mutations includes intellectual disability and autism spectrum disorder.

Studies of genomic copy number variants (CNVs) have identified genes associated with autism spectrum disorder (ASD) and intellectual disability (ID) such as NRXN1, SHANK2, SHANK3 and PTCHD1. Deletions have been reported in PTCHD1 however there has been little information available regarding the clinical presentation of these individuals. Herein we present 23 individuals with PTCHD1 deletions or truncating mutations with detailed phenotypic descriptions. The results suggest that individuals with disruption of the PTCHD1 coding region may have subtle dysmorphic features including a long face, prominent forehead, puffy eyelids and a thin upper lip. They do not have a consistent pattern of associated congenital anomalies or growth abnormalities. They have mild to moderate global developmental delay, variable degrees of ID, and many have prominent behavioral issues. Over 40% of subjects have ASD or ASD-like behaviors. The only consistent neurological findings in our cohort are orofacial hypotonia and mild motor incoordination. Our findings suggest that hemizygous PTCHD1 loss of function causes an X-linked neurodevelopmental disorder with a strong propensity to autistic behaviors. Detailed neuropsychological studies are required to better define the cognitive and behavioral phenotype.

A distinct microvascular endothelial gene expression profile in severe IUGR placentas.

The placental microvasculature is essential for efficient transfer of gases, nutrients and waste between the mother and fetus. Microvascular hypoplasia of the terminal villi is a common pathology in severe Intra Uterine Growth Restriction (IUGR). We used novel methods to obtain placental micro-vascular endothelial cells (PlMEC) from preterm control placentas (n = 3) and placentas from pregnancies with severe IUGR (n = 6) with absent or reversed end-diastolic velocity in the umbilical artery. Distal placental villous tissue was collected to enrich for intermediate and terminal villi. Tissue was digested and PlMEC positively selected using tocosylated magnetic Dynabeads labeled with Human Endothelial Antigen lectin. The purity of the PlMEC (94 ± 2 SD %) was assessed by CD31 and vimentin immunocytochemistry. RNA was extracted from the PlMEC samples and subjected to Affymetrix microarray analysis (U133Plus2 array chips). Comparison of preterm and IUGR PlMEC gene expression profiles identified BTNL9 and NTRK2 transcripts to be upregulated and SAA1 and SLAMF1 transcripts to be downregulated in all 6 IUGR cases relative to preterm controls. A third downregulated gene GNAS was identified to be near significance. Changes were demonstrated to be significant at the mRNA level by Real Time PCR in the PlMEC samples. Changes in the IUGR endothelium were confirmed at the protein level by immunohistochemistry for the 3 with available antibodies. We used a tissue microarray constructed from an independent cohort of placental samples from severe IUGR (n = 7), preeclamptic (n = 7), preterm control (n = 6) and term control (n = 6) pregnancies. Results confirmed differential endothelial expression of BTNL9, NTRK2 and SLAMF1 in IUGR versus preterm and term samples. These studies are the first to characterize PlMEC gene expression profiles thus we have advanced our understanding of the molecular basis of placental micro-vascular pathophysiology in fetal growth restriction.

Hemizygous deletions on chromosome 1p21.3 involving the DPYD gene in individuals with autism spectrum disorder.

We describe the identification and clinical presentation of four individuals from three unrelated families with hemizygous deletions involving the DPYD gene at chromosome 1p21.3. DPYD encodes dihydropyrimidine dehydrogenase, which is the initial and rate-limiting enzyme in the catabolism of pyrimidine bases. All four individuals described met diagnostic criteria for autism spectrum disorder with severe speech delay. Patient 1's deletion was originally reported in 2008, and more detailed clinical information is provided. Subsequently, this male individual was found to have a missense mutation in the X-linked PTCHD1 autism susceptibility gene, which may also contribute to the phenotype. Patients 2 and 3 are siblings with a novel deletion encompassing the DPYD gene. In their mother, the genomic region deleted from chromosome 1p21.3 was inserted into chromosome 10. A fourth proband had a novel 10-kb intragenic deletion of exon 6 of the DPYD gene detected on a higher resolution microarray. Our study suggests that hemizygous deletions involving the DPYD locus present with variable phenotypes which can include speech delay and autistic features, and may also be influenced by additional mutations in other genes, issues which need to be considered in genetic counseling.

EBV transformation and cell culturing destabilizes DNA methylation in human lymphoblastoid cell lines.

Recent research suggests that epigenetic alterations involving DNA methylation can be causative for neurodevelopmental, growth and metabolic disorders. Although lymphoblastoid cell lines have been an invaluable resource for the study of both genetic and epigenetic disorders, the impact of EBV transformation, cell culturing and freezing on epigenetic patterns is unknown. We compared genome-wide DNA methylation patterns of four white blood cell samples, four low-passage lymphoblastoid cell lines pre and post freezing and four high-passage lymphobastoid cell lines, using two microarray platforms: Illumina HumanMethylation27 platform containing 27,578 CpG sites and Agilent Human CpG island Array containing 27,800 CpG islands. Comparison of genome-wide methylation profiles between white blood cells and lymphoblastoid cell lines demonstrated methylation alterations in lymphoblastoid cell lines occurring at random genomic locations. These changes were more profound in high-passage cells. Freezing at low-passages did not have a significant effect on DNA methylation. Methylation changes were observed in several imprinted differentially methylated regions, including DIRAS3, NNAT, H19, MEG3, NDN and MKRN3, but not in known imprinting centers. Our results suggest that lymphoblastoid cell lines should be used with caution for the identification of disease-associated DNA methylation changes or for discovery of new imprinted genes, as the methylation patterns seen in these cell lines may not always be representative of DNA methylation present in the original B-lymphocytes of the patient.

New chromosome 11p15 epigenotypes identified in male monozygotic twins with Beckwith-Wiedemann syndrome.

Beckwith-Wiedemann syndrome (BWS) is an overgrowth syndrome demonstrating heterogeneous molecular alterations of two imprinted domains on chromosome 11p15. The most common molecular alterations include loss of methylation at the proximal imprinting center, IC2, paternal uniparental disomy (UPD) of chromosome 11p15 and hypermethylation at the distal imprinting center, IC1. An increased incidence of female monozygotic twins discordant for BWS has been reported. The molecular basis for eleven such female twin pairs has been demonstrated to be a loss of methylation at IC2, whereas only one male monozygotic twin pair has been reported with this molecular defect. We report here two new pairs of male monozygotic twins. One pair is discordant for BWS; the affected twin exhibits paternal UPD for chromosome 11p15 whereas the unaffected twin does not. The second male twin pair is concordant for BWS and both twins of the pair demonstrate hypermethylation at IC1. Thus, this report expands the known molecular etiologies for BWS twins. Interestingly, these findings demonstrate a new epigenotype-phenotype correlation in BWS twins. That is, while female monozygotic twins with BWS are likely to show loss of imprinting at IC2, male monozygotic twins with BWS reflect the molecular heterogeneity seen in BWS singletons. These data underscore the need for molecular testing in BWS twins, especially in view of the known differences among 11p15 epigenotypes with respect to tumor risk.

An inversion inv(4)(p12-p15.3) in autistic siblings implicates the 4p GABA receptor gene cluster.

INTRODUCTION: We describe the case of two brothers diagnosed with autism who both carry a paracentic inversion of the short arm of chromosome 4 (46,XY, inv(4)(p12-p15.3)). We have determined that this inversion is inherited from an apparently unaffected mother and unaffected maternal grandfather. Methods/ RESULTS: Using fluorescence in situ hybridisation analysis and Southern blot hybridisation we identified the breakpoints. The proximal breakpoint (4p12) maps to a region containing a cluster of gamma-aminobutyric acid A (GABA(A)) receptor genes, and directly interrupts the GABRG1 gene, the distal-most gene of the cluster. We also identified an insertion/deletion polymorphism for a approximately 2 kb LINE1 (L1) element that occurs within intron 7 of GABRG1. Our genotype analysis amongst autism families indicated that the L1 deletion allele did not show increased transmission to affected individuals. No linkage disequilibrium was evident between the L1 and single nucleotide polymorphisms in adjacent GABA(A) receptor genes on 4p, where a recent study has identified significant association with autism. DISCUSSION: Despite this, the identification of an inversion breakpoint disrupting GABRG1 provides solid support for the genetic involvement of the short arm of chromosome 4 in the genetic aetiology of autism, and for the hypothesis of disrupted GABA neurotransmission in autism.

Unbalanced placental expression of imprinted genes in human intrauterine growth restriction.

Imprinted genes control fetal and placental growth in mice and in rare human syndromes, but the role of these genes in sporadic intrauterine growth restriction (IUGR) is less well-studied. We measured the ratio of mRNA from a maternally expressed imprinted gene, PHLDA2, to that from a paternally expressed imprinted gene, MEST, by Northern blotting in 38 IUGR-associated placentae and 75 non-IUGR placentae and found an increase in the PHLDA2/MEST mRNA ratio in IUGR (p=0.0001). Altered expression of PHLDA2 and MEST was not accompanied by changes in DNA methylation within their imprinting centers, and immunohistochemistry showed PHLDA2 protein appropriately restricted to villous and intermediate cytotrophoblast in the IUGR placentae. We next did a genome-wide survey of mRNA expression in 14 IUGR placentae with maternal vascular under-perfusion compared to 15 non-IUGR placentae using Affymetrix U133A microarrays. In this series six imprinted genes were differentially expressed by ANOVA with a Benjamini-Hochberg false discovery rate of 0.05, with increased expression of PHLDA2 and decreased expression of MEST, MEG3, GATM, GNAS and PLAGL1 in IUGR placentae. At lower significance, we found IGF2 mRNA decreased and CDKN1C mRNA increased in the IUGR cases. We confirmed the significant reduction in MEG3 non-translated RNA in IUGR placentae by Northern blotting. In addition to imprinted genes, the microarray data highlighted non-imprinted genes acting in endocrine signaling (LEP, CRH, HPGD, INHBA), tissue growth (IGF1), immune modulation (INDO, PSG-family genes), oxidative metabolism (GLRX), vascular function (AGTR1, DSCR1) and metabolite transport (SLC-family solute carriers) as differentially expressed in IUGR vs. non-IUGR placentae.

The adult phenotype in Costello syndrome.

We report clinical findings in 17 adults with Costello syndrome ranging in age from 16 to 40 years. Two patients in this series have had bladder carcinoma, the only malignancy reported to affect adults with Costello syndrome. Benign tumors included multiple ductal papillomata in two women, and a fourth ventricle mass in one man, thought to be a choroid plexus papilloma. Endocrine problems in this series were osteoporosis, central hypogonadism, and delayed puberty. Other health problems were symptomatic Chiari malformations in three patients. Four patients had adult-onset gastro-esophageal reflux, three of whom had Chiari malformations. Fourteen adults had mild to moderate intellectual disability with three individuals having severe intellectual disability; 15 individuals attained some reading and writing skills and 14 showed ongoing acquisition of new skills into adulthood. On the basis of this data, we recommend that neuro-imaging be considered in adults with Costello syndrome if they develop symptoms suggestive of a Chiari malformation. In the event of pubertal delay, endocrine investigations are indicated and hormone treatment may be required. Bone density assessments should be performed in adults with Costello syndrome, particularly in those with pubertal abnormalities. Screening for microscopic hematuria as a marker for bladder carcinoma may be indicated, although this requires further evaluation.

Postmaturity in a genetic subtype of schizophrenia.

OBJECTIVE: To determine whether postmaturity (gestation > 41 weeks), small for gestational age (SGA), and other pregnancy and birth complications that may elevate risk for neurodevelopmental disorders, are associated with elevated risk for schizophrenia in 22q11 Deletion Syndrome (22qDS), a genetic subtype of schizophrenia. METHOD: Antepartum and intrapartum features were examined in 20 adults with 22qDS-schizophrenia and three comparison groups: newborn encephalopathy (n = 164) and healthy newborn controls (n = 400) from Badawi et al.'s (Br Med J 1998, 317: 1549) study, and 16 non-psychotic 22qDS adults (22qDS-NP). RESULTS: Postmaturity (OR 13.0, 95% CI 3.95, 42.77; P < 0.001) and SGA (OR 3.59, 95% CI 1.23, 10.5; P = 0.03) were more prevalent in 22qDS-SZ than controls. Postmaturity was non-significantly more prevalent in 22qDS-SZ than in newborn encephalopathy (P = 0.06) or 22qDS-NP (P = 0.2). SGA showed similar rates in the two 22qDS groups and newborn encephalopathy, but was more prevalent in 22qDS-NP than controls (P = 0.05). CONCLUSION: The results suggest that postmaturity may be associated with expression of schizophrenia in a 22qDS subtype of schizophrenia. SGA may be a non-specific marker of neurodevelopmental disturbance.

Linkage study in families with posterior helical ear pits and Wiedemann-Beckwith syndrome.

The Wiedemann-Beckwith syndrome (WBS) is defined by a group of anomalies, including macrosomia, macroglossia, omphalocele, and ear creases. Several minor anomalies have also been reported in the syndrome, including posterior helical ear pits (PHEP). Two independent linkage studies of pedigrees with autosomal dominant inheritance have shown linkage of WBS to 11p15.5 markers. Further confirming the location of WBS to this location is the finding of 11p15.5 duplications and translocations, as well as uniparental disomy for a small area of 11p15.5. In this study, members of previously described families exhibiting autosomal dominant inheritance of the PHEP phenotype were genotyped for three markers in the 11p15.5 region. These three markers were in the insulin-like growth factor (IGF2), insulin (INS), and tyrosine hydroxylase (TH) region. The data were examined by linkage analysis using the same genetic model used previously to demonstrate linkage of WBS to markers on chromosome 11p15.5: an autosomal dominant model with a penetrance of 0.90 and a gene frequency of 0.001. In one large pedigree, linkage analysis of the 11p15.5 markers excluded the PHEP phenotype from the IGF2, INS, and TH region. In the four other pedigrees examined, the marker loci were not sufficiently informative or the pedigrees did not provide sufficient power to exclude linkage from this region. The strongest evidence against linkage of the PHEP phenotype to 11p15.5 was evident by inspection of the segregation of the haplotypes of the markers in the pedigrees. In two informative pedigrees, relatives with the PHEP phenotype did not share the same haplotype of markers identical by descent. Our results show that the PHEP phenotype is not linked to chromosome 11p15.5 in the informative families tested. In the families examined, there are not enough individuals with WBS to determine if WBS was linked to 11p15.5 in these families. Although locus heterogeneity has not been demonstrated in WBS, it is possible that a second WBS locus exists and that the PHEP phenotype in these families is linked to a second WBS locus. Alternatively, the PHEP phenotype may occur independently of WBS so that the association of WBS and PHEP in our pedigrees may, in fact, represent causal heterogeneity.

Tumor development in the Beckwith-Wiedemann syndrome is associated with a variety of constitutional molecular 11p15 alterations including imprinting defects of KCNQ1OT1.

Dysregulation of imprinted genes on human chromosome 11p15 has been implicated in Beckwith-Wiedemann syndrome (BWS), an overgrowth syndrome associated with congenital malformations and tumor predisposition. The molecular basis of BWS is complex and heterogeneous. The syndrome is associated with alterations in two distinct imprinting domains on 11p15: a telomeric domain containing the H19 and IGF2 genes and a centromeric domain including the KCNQ1OT1 and CDKNIC genes. It has been postulated that disorders of imprinting in the telomeric domain are associated with overgrowth and cancer predisposition, whereas those in the centromeric domain involve malformations but not tumor development. In this study of 125 BWS cases, we confirm the association of tumors with constitutional defects in the 11p15 telomeric domain; six of 21 BWS cases with uniparental disomy (UPD) of 11p15 developed tumors and one of three of the rare BWS subtype with hypermethylation of the H19 gene developed tumors. Most importantly, we find that five of 32 individuals with BWS and imprinting defects in the centromeric domain developed embryonal tumors. Furthermore, the type of tumors observed in BWS cases with telomeric defects are different from those seen in BWS cases with defects limited to the centromeric domain. Whereas Wilms' tumor was the most frequent tumor seen in BWS cases with UPD for 11p15 or H19 hypermethylation, none of the embryonal tumors with imprinting defects at KCNQ1OT1 was a Wilms' tumor. This suggests that distinct tumor predisposition profiles result from dysregulation of the telomeric domain versus the centromeric domain and that these imprinting defects activate distinct genetic pathways for embryonal tumorigenesis.

GPC3 mutation analysis in a spectrum of patients with overgrowth expands the phenotype of Simpson-Golabi-Behmel syndrome.

Simpson-Golabi-Behmel syndrome (SGBS) is an X-linked overgrowth syndrome caused by deletions in glypican 3 (GPC3). SGBS is characterized by pre- and postnatal overgrowth, a characteristic facial appearance, and a spectrum of congenital malformations which overlaps that of other overgrowth syndromes. We performed GPC3 deletion screening on 80 male patients with somatic overgrowth in the following categories: SGBS (n = 19), possible SGBS (n = 26), including families in which individuals had previously been diagnosed with other overgrowth syndromes, and Wiedemann-Beckwith syndrome (WBS) (n = 35). Using exon-specific PCR and Southern blot analysis, we identified seven GPC3 deletions. In most cases a clear X-linked family history was not present. In two cases, GPC3 deletions were identified in patients belonging to pedigrees published previously as other overgrowth syndromes: one with a diagnosis of Sotos syndrome and the other Perlman syndrome with nephroblastomatosis. A third patient developed hepatoblastoma, a tumor type not previously described in SGBS. No GPC3 deletions were identified among the WBS patients. Direct sequencing of all GPC3 exons in the remaining 13 SGBS patients without GPC3 deletions did not identify any further mutations, raising the possibility of alternative silencing mechanisms and/or other genes in the pathogenesis of SGBS. Our results validate the clinical specificity of the facial appearance, skeletal/hand anomalies, and supernumerary nipples in patients with GPC3 deletions. Our data also suggest that nephroblastomatosis and hepatoblastoma are included in the phenotypic spectrum of GPC3 deletions and SGBS, underscoring the importance of tumor surveillance in these children.

Low platelet count in a 22q11 deletion syndrome subtype of schizophrenia.

BACKGROUND: 22q11 Deletion Syndrome (22qDS) is a genetic syndrome associated with various physical features and schizophrenia. Some reports have identified thrombocytopenia (platelet count < 150 x 10(9)/l) in individuals with 22qDS, especially children. We investigated whether adults with 22qDS and schizophrenia (22qDS-SZ) have lower platelet counts than other patients with schizophrenia (SZ). METHOD: Complete blood counts (CBC) were recorded from medical records for 18 22qDS-SZ and 60 SZ subjects. Five CBCs per subject were randomly selected and used to calculate a within-subject mean for analyses. RESULTS: 22qDS-SZ subjects had significantly lower mean platelet counts than comparison SZ subjects (142.2 x 10(9)/l versus 282.5 x 10(9)/l, t = -11.5, p < 0.0001). Ten 22qDS-SZ (55%) and no comparison subjects had thrombocytopenia. CONCLUSIONS: These results suggest that thrombocytopenia may be a common feature of 22qDS and that low platelet counts may comprise a readily available screening criterion to help identify this genetic syndrome among adults with schizophrenia.

Imprinting status of 11p15 genes in Beckwith-Wiedemann syndrome patients with CDKN1C mutations.

Beckwith-Wiedemann syndrome (BWS) is an imprinting disorder characterized by somatic overgrowth, congenital malformations, and predisposition to childhood tumors. Aberrant expression of multiple imprinted genes, including H19, IGF2, KCNQ1OT1, and CDKN1C, has been observed in BWS patients. It has been estimated that mutations in CDKN1C occur in 12-17% of BWS patients. We have screened 10 autosomal dominant pedigrees and 65 sporadic BWS cases by PCR/heteroduplex analysis and DNA sequencing and have identified four mutations, two of which were associated with biallelic IGF2 expression and normal H19 and KCNQ1OT1 imprinting. One patient demonstrated phenotypic expression of paternally transmitted mutation in this maternally expressed gene, a second proband is the child of one of a pair of monozygotic twin females who carry the mutation de novo, and a third patient exhibited unusual skeletal changes more commonly found in other overgrowth syndromes. When considered with other studies published to date, this work reveals the frequency of CDKN1C mutations in BWS to be only 4.9%. This is the first report of an analysis of the imprinting status of genes in the 11p15 region where CDKN1C mutations were associated with loss of IGF2 imprinting and maintenance of H19 and KCNQ1OT1 imprinting.

Association of alveolar rhabdomyosarcoma with the Beckwith-Wiedemann syndrome.

Rhabdomyosarcoma (RMS) is a soft tissue tumor of childhood frequently diagnosed between the first and fifth year of life. Children with the Beckwith-Wiedemann syndrome (BWS), a congenital overgrowth syndrome characterized by exomphalos, macroglossia, and macrosomia, have an increased risk of developing childhood tumors including Wilms tumor, hepatoblastoma, neuroblastoma, and RMS. Although an association between RMS and the BWS is well accepted, only four cases have been reported to date, and of these, three were reported as embryonal RMS. Based on these data, an association between BWS and embryonal RMS has been proposed. We report three additional cases of BWS with RMS and review the clinical data for each patient as well as the pathology of their tumors. All three cases of BWS had histology consistent with alveolar RMS and were diagnosed at 6 weeks and 5 and 13 years of age. In two of these BWS cases, constitutional defects of 11p15 imprinting were demonstrated. Furthermore, cytogenetic analysis of the tumors did not detect the t(2;13) or t(1;13) translocations that generate the PAX3- or PAX7-FKHR fusion proteins common to alveolar RMS. These observations suggest that the development of alveolar RMS tumors in BWS may occur without the chromosomal rearrangement producing the PAX-FKHR fusion protein. In summary, we present three new cases of RMS demonstrating a new association between BWS and an uncommon subtype of alveolar RMS. The absence of the translocations commonly associated with alveolar rhabdomyosarcoma suggests a common 11p15 pathway for alveolar RMS and BWS.

Patterns of dysmorphic features in schizophrenia.

Congenital dysmorphic features are prevalent in schizophrenia and may reflect underlying neurodevelopmental abnormalities. A cluster analysis approach delineating patterns of dysmorphic features has been used in genetics to classify individuals into more etiologically homogeneous subgroups. In the present study, this approach was applied to schizophrenia, using a sample with a suspected genetic syndrome as a testable model. Subjects (n = 159) with schizophrenia or schizoaffective disorder were ascertained from chronic patient populations (random, n = 123) or referred with possible 22q11 deletion syndrome (referred, n = 36). All subjects were evaluated for presence or absence of 70 reliably assessed dysmorphic features, which were used in a three-step cluster analysis. The analysis produced four major clusters with different patterns of dysmorphic features. Significant between-cluster differences were found for rates of 37 dysmorphic features (P < 0.05), median number of dysmorphic features (P = 0.0001), and validating features not used in the cluster analysis: mild mental retardation (P = 0.001) and congenital heart defects (P = 0.002). Two clusters (1 and 4) appeared to represent more developmental subgroups of schizophrenia with elevated rates of dysmorphic features and validating features. Cluster 1 (n = 27) comprised mostly referred subjects. Cluster 4 (n = 18) had a different pattern of dysmorphic features; one subject had a mosaic Turner syndrome variant. Two other clusters had lower rates and patterns of features consistent with those found in previous studies of schizophrenia. Delineating patterns of dysmorphic features may help identify subgroups that could represent neurodevelopmental forms of schizophrenia with more homogeneous origins.

Music skills and the expressive interpretation of music in children with Williams-Beuren syndrome: pitch, rhythm, melodic imagery, phrasing, and musical affect.

This paper studied music in 14 children and adolescents with Williams-Beuren syndrome (WBS), a multi-system neurodevelopmental disorder, and 14 age-matched controls. Five aspects of music were tested. There were two tests of core music domains, pitch discrimination and rhythm discrimination. There were two tests of musical expressiveness, melodic imagery and phrasing. There was one test of musical interpretation, the ability to identify the emotional resonance of a musical excerpt. Music scores were analyzed by means of logistic regressions that modeled outcome (higher or lower music scores) as a function of group membership (WBS or Control) and cognitive age. Compared to age peers, children with WBS had similar levels of musical expressiveness, but were less able to discriminate pitch and rhythm, or to attach a semantic interpretation to emotion in music. Music skill did not vary with cognitive age. Musical strength in individuals with WBS involves not so much formal analytic skill in pitch and rhythm discrimination as a strong engagement with music as a means of expression, play, and, perhaps, improvisation.