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Nuclear receptor subfamily 2 group F member 2 (NR2F2or COUP-TF2) encodes a transcription factor which is expressed at high levels during mammalian development. Rare heterozygous Mendelian variants in NR2F2were initially identified in individuals with congenital heart disease (CHD), then subsequently in cohorts of congenital diaphragmatic hernia (CDH) and 46,XX ovotesticular disorders/differences of sexual development (DSD); however, the phenotypic spectrum associated with pathogenic variants in NR2F2remains poorly characterized. Currently, less than 40 individuals with heterozygous pathogenic variants in NR2F2have been reported. Here, we review the clinical and molecular details of 17 previously unreported individuals with rare heterozygous NR2F2variants, the majority of which were de novo. Clinical features were variable, including intrauterine growth restriction (IUGR), CHD, CDH, genital anomalies, DSD, developmental delays, hypotonia, feeding difficulties, failure to thrive, congenital and acquired microcephaly, dysmorphic facial features, renal failure, hearing loss, strabismus, asplenia, and vascular malformations, thus expanding the phenotypic spectrum associated with NR2F2variants. The variants seen were predicted loss of function, including a nonsense variant inherited from a mildly affected mosaic mother, missense and a large deletion including the NR2F2gene. Our study presents evidence for rare, heterozygous NR2F2variants causing a highly variable syndrome of congenital anomalies, commonly associated with heart defects, developmental delays/intellectual disability, dysmorphic features, feeding difficulties, hypotonia, and genital anomalies. Based on the new and previous cases, we provide clinical recommendations for evaluating individuals diagnosed with an NR2F2-associated disorder.

Germline loss-of-function variants in CTNNB1cause neurodevelopmental disorder with spastic diplegia and visual defects (NEDSDV; OMIM 615075) and are the most frequent, recurrent monogenic cause of cerebral palsy (CP). We investigated the range of clinical phenotypes owing to disruptions of CTNNB1to determine the association between NEDSDV and CP.

Hardikar syndrome (HS, MIM #301068) is a female-specific multiple congenital anomaly syndrome characterized by retinopathy, orofacial clefting, aortic coarctation, biliary dysgenesis, genitourinary malformations, and intestinal malrotation. We previously showed that heterozygous nonsense and frameshift variants in MED12cause HS. The phenotypic spectrum of disease and the mechanism by which MED12variants cause disease is unknown. We aim to expand the phenotypic and molecular landscape of HS and elucidate the mechanism by which MED12variants cause disease.

Central conducting lymphatic anomaly (CCLA) is a heterogenous disorder caused by disruption of central lymphatic flow that may result in dilation or leakage of central lymphatic channels. There is also a paucity of known genetic diagnoses associated with CCLA. We hypothesized that specific genetic syndromes would have distinct lymphatic patterns and this would allow us to more precisely define CCLA. As a first step toward “precision lymphology”, we defined the genetic conditions associated with CCLA by performing a retrospective cohort study. Individuals receiving care through the Jill and Mark Fishman Center for Lymphatic Disorders at the Children’s Hospital of Philadelphia between 2016 and 2019 were included if they had a lymphangiogram and clinical genetic testing performed and consented to a clinical registry. In our cohort of 115 participants, 26% received a molecular diagnosis from standard genetic evaluation. The most common genetic etiologies were germline and mosaic RASopathies, chromosomal abnormalities including Trisomy 21 and 22q11.2 deletion syndrome, and PIEZO1-related lymphatic dysplasia. Next, we analyzed the dynamic contrast magnetic resonance lymphangiograms and found that individuals with germline and mosaic RASopathies, mosaic KRASopathies, PIEZO1-related lymphatic dysplasia, and Trisomy 21 had distinct central lymphatic flow phenotypes. Our research expands the genetic conditions associated with CCLA and genotype-lymphatic phenotype correlations. Future descriptions of CCLA should include both genotype (if known) and phenotype to provide more information about disease (gene-CCLA). This should be considered for updated classifications of CCLA by the International Society of Vascular Anomalies.

22q11.2 deletion syndrome (22q11.2DS) is the most common chromosomal microdeletion syndrome and has a multisystemic presentation including gastrointestinal features that have not yet been fully described. Our aim was to examine lifetime gastrointestinal problems in a large cohort of patients with 22q11.2DS. All patients followed in the 22q and You Center at the Children's Hospital of Philadelphia (n = 1421) were retrospectively screened for: 1) age ≥17 years, 2) documented chromosomal microdeletion within the 22q11.2 LCR22A‐LCR22D region, and 3) sufficient clinical data to characterize the adult gastrointestinal phenotype. Gastrointestinal problems in childhood, adolescence, and adulthood were summarized. Statistical association testing of symptoms against other patient characteristics was performed. Included patients (n = 206; 46% female; mean age, 27 years; median follow‐up, 21 years) had similar clinical characteristics to the overall cohort. Genetic distribution was also similar, with 96% having deletions including the critical LCR22A‐LCR22B segment (95% in the overall cohort). Most patients experienced chronic gastrointestinal symptoms in their lifetime (91%), but congenital gastrointestinal malformations (3.5%) and gastrointestinal autoimmune diseases (1.5%) were uncommon. Chronic symptoms without anatomic or pathologic abnormalities represented the vast burden of illness. Chronic symptoms in adulthood are associated with other chronic gastrointestinal symptoms and psychiatric comorbidities (P< 0.01) but not with deletion size or physiologic comorbidities (P> 0.05). One exception was increased nausea/vomiting in hypothyroidism (P= 0.002). Functional gastrointestinal disorders (FGIDs) are a common cause of ill health in children and adults with 22q11.2DS. Providers should consider screening for the deletion in patients presenting with FGIDs and associated comorbidities such as neuropsychiatric illness, congenital heart disease, and palatal abnormalities.

Clinical exome sequencing (CES) aids in the diagnosis of rare genetic disorders. Herein, we report the molecular diagnostic yield and spectrum of genetic alterations contributing to disease in 700 pediatric cases analyzed at the Children's Hospital of Philadelphia. The overall diagnostic yield was 23%, with three cases having more than one molecular diagnosis and 2.6% having secondary/additional findings. A candidate gene finding was reported in another 8.4% of cases. The clinical indications with the highest diagnostic yield were neurodevelopmental disorders (including seizures), whereas immune- and oncology-related indications were negatively associated with molecular diagnosis. The rapid expansion of knowledge regarding the genome's role in human disease necessitates reanalysis of CES samples. To capture these new discoveries, a subset of cases (n = 240) underwent reanalysis, with an increase in diagnostic yield. We describe our experience reporting CES results in a pediatric setting, including reporting of secondary findings, reporting newly discovered genetic conditions, and revisiting negative test results. Finally, we highlight the challenges associated with implementing critical updates to the CES workflow. Although these updates are necessary, they demand an investment of time and resources from the laboratory. In summary, these data demonstrate the clinical utility of exome sequencing and reanalysis, while highlighting the critical considerations for continuous improvement of a CES test in a clinical laboratory.

We previously defined biallelic HYAL2variants causing a novel disorder in 2 families, involving orofacial clefting, facial dysmorphism, congenital heart disease, and ocular abnormalities, with Hyal2knockout mice displaying similar phenotypes. In this study, we better define the phenotype and pathologic disease mechanism.

Chromosome 22q11.2 deletion syndrome (22q11.2DS) is a multisystem disorder associated with multiple congenital anomalies, variable medical features, and neurodevelopmental differences resulting in diverse psychiatric phenotypes, including marked deficits in facial memory and social cognition. Neuroimaging in individuals with 22q11.2DS has revealed differences relative to matched controls in BOLD fMRI activation during facial affect processing tasks. However, time-varying interactions between brain areas during facial affect processing have not yet been studied with BOLD fMRI in 22q11.2DS. We applied constrained principal component analysis to identify temporally overlapping brain activation patterns from BOLD fMRI data acquired during an emotion identification task from 58 individuals with 22q11.2DS and 58 age-, race-, and sex-matched healthy controls. Delayed frontal-motor feedback signals were diminished in individuals with 22q11.2DS, as were delayed emotional memory signals engaging amygdala, hippocampus, and entorhinal cortex. Early task-related engagement of motor and visual cortices and salience-related insular activation were relatively preserved in 22q11.2DS. Insular activation was associated with task performance within the 22q11.2DS sample. Differences in cortical surface area, but not cortical thickness, showed spatial alignment with an activation pattern associated with face processing. These findings suggest that relative to matched controls, primary visual processing and insular function are relatively intact in individuals with 22q11.22DS, while motor feedback, face processing, and emotional memory processes are more affected. Such insights may help inform potential interventional targets and enhance the specificity of neuroimaging indices of cognitive dysfunction in 22q11.2DS.

BackgroundA neurodevelopmental syndrome was recently reported in four patients with SOX4heterozygous missense variants in the high-mobility-group (HMG) DNA-binding domain. The present study aimed to consolidate clinical and genetic knowledge of this syndrome.MethodsWe newly identified 17 patients with SOX4variants, predicted variant pathogenicity using in silico tests and in vitro functional assays and analysed the patients’ phenotypes.ResultsAll variants were novel, distinct and heterozygous. Seven HMG-domain missense and five stop-gain variants were classified as pathogenic or likely pathogenic variant (L/PV) as they precluded SOX4 transcriptional activity in vitro. Five HMG-domain and non-HMG-domain missense variants were classified as of uncertain significance (VUS) due to negative results from functional tests. When known, inheritance was de novo or from a mosaic unaffected or non-mosaic affected parent for patients with L/PV, and from a non-mosaic asymptomatic or affected parent for patients with VUS. All patients had neurodevelopmental, neurological and dysmorphic features, and at least one cardiovascular, ophthalmological, musculoskeletal or other somatic anomaly. Patients with L/PV were overall more affected than patients with VUS. They resembled patients with other neurodevelopmental diseases, including the SOX11-related and Coffin-Siris (CSS) syndromes, but lacked the most specific features of CSS.ConclusionThese findings consolidate evidence of a fairly non-specific neurodevelopmental syndrome due to SOX4haploinsufficiency in neurogenesis and multiple other developmental processes.

Rare genetic variants in KDR, encoding the vascular endothelial growth factor receptor 2 (VEGFR2), have been reported in patients with tetralogy of Fallot (TOF). However, their role in disease causality and pathogenesis remains unclear.

Schizophrenia occurs in about one in four individuals with 22q11.2 deletion syndrome (22q11.2DS). The aim of this International Brain and Behavior 22q11.2DS Consortium (IBBC) study was to identify genetic factors that contribute to schizophrenia, in addition to the ~20-fold increased risk conveyed by the 22q11.2 deletion. Using whole-genome sequencing data from 519 unrelated individuals with 22q11.2DS, we conducted genome-wide comparisons of common and rare variants between those with schizophrenia and those with no psychotic disorder at age ≥25 years. Available microarray data enabled direct comparison of polygenic risk for schizophrenia between 22q11.2DS and independent population samples with no 22q11.2 deletion, with and without schizophrenia (total n= 35,182). Polygenic risk for schizophrenia within 22q11.2DS was significantly greater for those with schizophrenia (padj= 6.73 × 10−6). Novel reciprocal case–control comparisons between the 22q11.2DS and population-based cohorts showed that polygenic risk score was significantly greater in individuals with psychotic illness, regardless of the presence of the 22q11.2 deletion. Within the 22q11.2DS cohort, results of gene-set analyses showed some support for rare variants affecting synaptic genes. No common or rare variants within the 22q11.2 deletion region were significantly associated with schizophrenia. These findings suggest that in addition to the deletion conferring a greatly increased risk to schizophrenia, the risk is higher when the 22q11.2 deletion and common polygenic risk factors that contribute to schizophrenia in the general population are both present.

Hardikar syndrome (MIM 612726) is a rare multiple congenital anomaly syndrome characterized by facial clefting, pigmentary retinopathy, biliary anomalies, and intestinal malrotation, but with preserved cognition. Only four patients have been reported previously, and none had a molecular diagnosis. Our objective was to identify the genetic basis of Hardikar syndrome (HS) and expand the phenotypic spectrum of this disorder.

There has been one previous report of a cohort of patients with variants in Chromodomain Helicase DNA-binding 3 (CHD3), now recognized as Snijders Blok-Campeau syndrome. However, with only three previously-reported patients with variants outside the ATPase/helicase domain, it was unclear if variants outside of this domain caused a clinically similar phenotype. We have analyzed 24 new patients with CHD3variants, including nine outside the ATPase/helicase domain. All patients were detected with unbiased molecular genetic methods. There is not a significant difference in the clinical or facial features of patients with variants in or outside this domain. These additional patients further expand the clinical and molecular data associated with CHD3variants. Importantly we conclude that there is not a significant difference in the phenotypic features of patients with various molecular disruptions, including whole gene deletions and duplications, and missense variants outside the ATPase/helicase domain. This data will aid both clinical geneticists and molecular geneticists in the diagnosis of this emerging syndrome.

Clinical next-generation sequencing is an effective approach for identifying pathogenic sequence variants that are medically actionable for participants and families but are not associated with the participant's primary diagnosis. These variants are called secondary findings (SFs). According to the literature, there is no report of the types and frequencies of SFs in a large pediatric cohort which includes substantial African-American participants. We sought to investigate the types (including American College of Medical Genetics and Genomics [ACMG] and non-ACMG recommended gene lists), frequencies, and rates of SFs, as well as the effects of SF disclosure on the participants and families of a large pediatric cohort at the Center for Applied Genomics at The Children’s Hospital of Philadelphia (CHOP).

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Chromosome 22q11.2 deletion syndrome (22q11DS) is associated with impairment in multiple domains of cognition and risk for several psychiatric disorders. Musical auditory processing is highly heritable, and is impaired in individuals with schizophrenia and other neurodevelopmental disorders, but has never been studied in 22q11DS, notwithstanding anecdotal evidence of its sparing. We aimed to characterize musical auditory processing in 22q11DS and explore potential relationships with other cognitive domains, musical engagement, and psychiatric disorders. The Distorted Tunes Task and Global Musical Sophistication Index were used to assess pitch discrimination and general musical engagement in 58 individuals with 22q11DS aged 8–29 years. Psychopathology was assessed with sections from the modified Schedule for Affective Disorders and Schizophrenia for School‐Age Children and the Structured Interview for Prodromal Syndromes. The Penn computerized neurocognitive battery (CNB) examined four domains of cognition (executive functioning, episodic memory, complex cognition, and social cognition). Significant musical auditory processing impairment and reduced musical engagement were found in individuals with 22q11DS. However, deficits in musical auditory processing were not associated with reduced musical engagement. After covarying for age and sex, episodic memory and overall CNB performance accuracy were significantly related to performance in musical auditory processing. There were no relationships between musical auditory processing and presence of any psychiatric diagnoses. Individuals with 22q11DS experience significant deficits in musical auditory processing and reduced musical engagement. Pitch discrimination is associated with overall cognitive ability, but appears to be largely independent of psychiatric illness.

Studies have previously implicated PRRX1 in craniofacial development, including demonstration of murine Prrx1expression in the preosteogenic cells of the cranial sutures. We investigated the role of heterozygous missense and loss-of-function (LoF) variants in PRRX1associated with craniosynostosis.

PurposeThe objective of this study was to assess the ability of our laboratory’s exome-sequencing test to detect known and novel sequence variants and identify the critical factors influencing the interpretation of a clinical exome test.MethodsWe developed a two-tiered validation strategy: (i) a method-based approach that assessed the ability of our exome test to detect known variants using a reference HapMap sample, and (ii) an interpretation-based approach that assessed our relative ability to identify and interpret disease-causing variants, by analyzing and comparing the results of 19 randomly selected patients previously tested by external laboratories.ResultsWe demonstrate that this approach is reproducible with >99% analytical sensitivity and specificity for single-nucleotide variants and indels <10 bp. Our findings were concordant with the reference laboratories in 84% of cases. A new molecular diagnosis was applied to three cases, including discovery of two novel candidate genes.ConclusionWe provide an assessment of critical areas that influence interpretation of an exome test, including comprehensive phenotype capture, assessment of clinical overlap, availability of parental data, and the addressing of limitations in database updates. These results can be used to inform improvements in phenotype-driven interpretation of medical exomes in clinical and research settings.

Crouzon syndrome with acanthosis nigricans (CAN) is caused by a mutation in the fibroblast growth factor receptor (FGFR) 3 gene that presents clinically as Crouzonoid craniofacial features in association with other anomalies such as acanthosis nigricans and benign odontogenic tumors. Diagnosis through the use of genetic mutational analysis is critical, as it alerts the surgeon to the need for careful screening for jaw tumors so that timely treatment in the form of curettage or segmental resection can be provided.

AbstractBackgroundWe have previously shown that the minor alleles of vascular endothelial growth factor A (VEGFA) single-nucleotide polymorphism rs833069 and superoxide dismutase 2 (SOD2)single-nucleotide polymorphism rs2758331 are both associated with improved transplant-free survival after surgery for CHD in infants, but the underlying mechanisms are unknown. We hypothesised that one or both of these minor alleles are associated with better systemic ventricular function, resulting in improved survival.MethodsThis study is a follow-up analysis of 422 non-syndromic CHD patients who underwent neonatal cardiac surgery with cardiopulmonary bypass. Echocardiographic reports were reviewed. Systemic ventricular function was subjectively categorised as normal, or as mildly, moderately, or severely depressed. The change in function was calculated as the change from the preoperative study to the last available study. Stepwise linear regression, adjusting for covariates, was performed for the outcome of change in ventricular function. Model comparison was performed using Akaike’s information criterion. Only variables that improved the model prediction of change in systemic ventricular function were retained in the final model.ResultsGenetic and echocardiographic data were available for 335/422 subjects (79%). Of them, 33 (9.9%) developed worse systemic ventricular function during a mean follow-up period of 13.5 years. After covariate adjustment, the presence of the VEGFAminor allele was associated with preserved ventricular function (p=0.011).ConclusionsThese data support the hypothesis that the mechanism by which the VEGFAsingle-nucleotide polymorphism rs833069 minor allele improves survival may be the preservation of ventricular function. Further studies are needed to validate this genotype–phenotype association and to determine whether this mechanism is related to increased vascular endothelial growth factor production.

This study aimed to establish variants in CBX1, encoding heterochromatin protein 1β (HP1β), as a cause of a novel syndromic neurodevelopmental disorder.

Atypical development, behavioral difficulties, and academic underachievement are common morbidities in children with a history of congenital heart defects and impact quality of life. Language and social‐cognitive deficits have been described, which are associated with autism spectrum disorders. The current study aimed to assess the rates of autism spectrum disorders in a large sample of children with a history of congenital heart defects and to assess medical, behavioral, and individual factors that may be associated with the risk of autism spectrum disorders. Participants included 195 children with a history of congenital heart defects, who are followed in a large‐scale longitudinal study. Measures included behavioral data from 4‐year‐old neurodevelopmental evaluations and parent‐report data from a later annual follow‐up. Using established cutoffs on an autism spectrum disorder screener, children with congenital heart defects showed higher rates of “possible” autism spectrum disorders than national rates, (Chi‐square Test of Equal Proportions), all Ps < .05. A stepwise variable selection method was used to create a “best prediction model” and multivariable logistic regression was used to identify variables predicting diagnostic status. Factors associated with diagnostic risk included medical (delayed sternal closure, prematurity, positive genetic findings), behavioral (cognitive, language, attention issues), and individual (socioeconomic, cultural/racial) variables. ROC analyses identified a cutoff of 7 to maximize sensitivity/specificity based on parent‐reported diagnosis. Risk of autism spectrum disorder screening status in children with congenital heart defects was higher than expected from population rates. Findings highlight the need for referral to a specialist to assess the presence and severity of social‐communication issues and congenital heart defects population‐specific screening thresholds for children with concern for autism spectrum disorders.

Purpose:Because a tracheal cartilaginous sleeve (TCS) confers a significant mortality risk that can be mitigated with appropriate intervention, we sought to describe the prevalence and associated genotypes in a large cohort of children with syndromic craniosynostosis.Methods:Chart review of patients with syndromic craniosynostosis across two institutions.Results:In a cohort of 86 patients with syndromic craniosynostosis, 31 required airway evaluation under anesthesia. TCS was found in 19, for an overall prevalence of 22%. FGFR2, TWIST1, and FGFR3 mutations were identified in children with TCS. All five children with a W290C mutation in FGFR2 had TCS, and most previously reported children with W290C had identification of TCS or early death. In contrast, TCS was not associated with other mutations at residue 290.Conclusion:There is an association between TCS and syndromic craniosynostosis, and it appears to be particularly high in individuals with the W290C mutation in FGFR2. Referral to a pediatric otolaryngologist and consideration of operative airway evaluation (i.e., bronchoscopy or rigid endoscopy) in all patients with syndromic craniosynostosis should be considered to evaluate for TCS. Results from genetic testing may help providers weigh the risks and benefits of early airway evaluation and intervention in children with higher-risk genotypes.Genet Med 19 1, 62–68.

BackgroundWe aimed for a comprehensive delineation of genetic, functional and phenotypic aspects of GRIN2Bencephalopathy and explored potential prospects of personalised medicine.MethodsData of 48 individuals with de novo GRIN2Bvariants were collected from several diagnostic and research cohorts, as well as from 43 patients from the literature. Functional consequences and response to memantine treatment were investigated in vitro and eventually translated into patient care.ResultsOverall, de novo variants in 86 patients were classified as pathogenic/likely pathogenic. Patients presented with neurodevelopmental disorders and a spectrum of hypotonia, movement disorder, cortical visual impairment, cerebral volume loss and epilepsy. Six patients presented with a consistent malformation of cortical development (MCD) intermediate between tubulinopathies and polymicrogyria. Missense variants cluster in transmembrane segments and ligand-binding sites. Functional consequences of variants were diverse, revealing various potential gain-of-function and loss-of-function mechanisms and a retained sensitivity to the use-dependent blocker memantine. However, an objectifiable beneficial treatment response in the respective patients still remains to be demonstrated.ConclusionsIn addition to previously known features of intellectual disability, epilepsy and autism, we found evidence that GRIN2Bencephalopathy is also frequently associated with movement disorder, cortical visual impairment and MCD revealing novel phenotypic consequences of channelopathies.

BackgroundCohesinopathies are rare neurodevelopmental disorders arising from a dysfunction in the cohesin pathway, which enables chromosome segregation and regulates gene transcription. So far, eight genes from this pathway have been reported in human disease. STAG1belongs to the STAG subunit of the core cohesin complex, along with five other subunits. This work aimed to identify the phenotype ascribed to STAG1mutations.MethodsAmong patients referred for intellectual disability (ID) in genetics departments worldwide, array-comparative genomic hybridisation (CGH), gene panel, whole-exome sequencing or whole-genome sequencing were performed following the local diagnostic standards.ResultsA mutation in STAG1was identified in 17 individuals from 16 families, 9 males and 8 females aged 2–33 years. Four individuals harboured a small microdeletion encompassing STAG1; three individuals from two families had an intragenic STAG1deletion. Six deletions were identified by array-CGH, one by whole-exome sequencing. Whole-exome sequencing found de novo heterozygous missense or frameshift STAG1variants in eight patients, a panel of genes involved in ID identified a missense and a frameshift variant in two individuals. The 17 patients shared common facial features, with wide mouth and deep-set eyes. Four individuals had mild microcephaly, seven had epilepsy.ConclusionsWe report an international series of 17 individuals from 16 families presenting with syndromic unspecific ID that could be attributed to a STAG1deletion or point mutation. This first series reporting the phenotype ascribed to mutation in STAG1highlights the importance of data sharing in the field of rare disorders.

Because a tracheal cartilaginous sleeve (TCS) confers a significant mortality risk that can be mitigated with appropriate intervention, we sought to describe the prevalence and associated genotypes in a large cohort of children with syndromic craniosynostosis.

22q11.2 Deletion Syndrome (22q11DS) is a multisystem disorder caused by a hemizygous deletion within 22q11.2. Patients with the deletion display a wide range of cognitive deficits. The gene catechol‐O‐methyl‐transferase (COMT) resides in the typically deleted region of 22q11.2 and is rendered hemizygous in individuals affected by the 22q11DS. COMT is a critical enzyme in the degradation of catecholamine neurotransmitters in the brain. A functional polymorphism, Val158Met, has been associated with a variety of neurocognitive outcomes. In this study, 159 patients with 22q11DS were analyzed for a potential association between intelligence quotient (IQ) and COMT genotype. We performed a univariate analysis for overall influence and modified our analysis to focus on possible differences between average, borderline, and intellectually impaired patients. No correlation between COMT genotype and IQ performance was found. © 2016 Wiley Periodicals, Inc.

Purpose:Maternal uniparental disomy of chromosome 20 (UPD(20)mat) has been reported in only four patients, three of whom also had mosaicism for complete or partial trisomy of chromosome 20. We sought to evaluate the clinical significance of isolated UPD(20)mat in eight individuals.Methods:We evaluated phenotypic and genomic findings of a series of eight new patients with UPD(20)mat.Results:All eight individuals with UPD(20)mat had intrauterine growth restriction, short stature, and prominent feeding difficulties with failure to thrive. As a common feature, they often required gastric tube feeds. Genomic data in most patients are indicative of UPD as a result of trisomy rescue after meiosis II nondisjunction.Conclusion:We describe the first natural history of the disorder and the results of therapeutic interventions, including the frequent requirement of direct gastric feedings only during the first few years of life, and propose that growth hormone supplementation is probably safe and effective for this condition. We suggest that UPD(20)mat can be regarded as a new imprinting disorder and its identification requires specialized molecular testing, which should be performed in patients with early-onset idiopathic isolated growth failure.Genet Med 18 4, 309–315.

Maternal uniparental disomy of chromosome 20 (UPD(20)mat) has been reported in only four patients, three of whom also had mosaicism for complete or partial trisomy of chromosome 20. We sought to evaluate the clinical significance of isolated UPD(20)mat in eight individuals.

Objective To determine the prevalence of cardiac, cervical spine, and carotid artery abnormalities in patients with 22q11.2 deletion syndrome (22q11.2DS) undergoing surgery for velopharyngeal dysfunction (VPD), associations between the presence of these abnormalities, and whether these abnormalities caused changes in surgical management or perioperative complications.Design Retrospective review.Setting Tertiary pediatric hospital.Patients Seventy patients with 22q11.2DS with complete preoperative cervical vascular and spine imaging and cardiac evaluation between 1998 and 2011.Main Outcome Measures Incidence of cardiac, cervical spine, and vascular abnormalities; related perioperative complications; and resulting changes in surgical, anesthetic, or perioperative management plan.Results Cardiac abnormalities occurred in 45 patients (64.3%), and 8 patients required cardiac anesthesia. Thirty-eight patients (54.3%) had at least one vascular abnormality of the neck, and 14% had medial deviation of the internal carotid artery. Surgery was not performed in one patient, and the surgical plan was altered in three patients because of carotid anomalies. Cervical spine abnormalities were found in 24 patients (34.3%); 8 patients demonstrated radiographic evidence of cervical instability and were treated with spinal precautions during surgery. The presence of one anomaly was not predictive of any other finding, and there were no complications related to the heart, cervical spine, or carotid arteries.Conclusions Anomalies of the heart, cervical spine, and cervical vasculature occur frequently in 22q11.2DS, vary drastically in severity, and are impossible to predict based on other features of the syndrome. Preoperative diagnosis of these comorbidities with routine imaging can minimize the risk of avoidable surgical complications.

Melorheostosis is a progressive hyperostotic bone disease that commonly affects the appendicular skeleton. Melorheostosis has a significant degree of overlap with other hyperostosis conditions including osteopoikilosis and likely represent varying degrees of a clinical spectrum.