Publications by authors named "Stephanie Sacharow"

25 Publications

  • Page 1 of 1

Hereditary orotic aciduria (HOA): A novel uridine-5-monophosphate synthase () mutation.

Mol Genet Metab Rep 2021 Mar 9;26:100703. Epub 2021 Jan 9.

Department of Pediatrics, Division of Metabolic Genetics, Sheikh Khalifa Medical City, Abu Dhabi, United Arab Emirates.

Hereditary orotic aciduria (HOA) is a very rare inborn error of pyrimidine metabolism. It results from a defect of the uridine-5-monophosphate synthase () gene. To date, only about twenty patients have been described. We report a case of HOA with a novel variant in the gene. A 17-year-old Emirati girl was born to first-cousin parents. During the first year, she had recurrent, severe infections including disseminated varicella. After evaluation for immunodeficiency, an impression of immunodeficiency of unknown etiology was presumed. Frequent episodes of pancytopenia were also noted. Bone marrow biopsy showed trilineage megaloblastoid maturation with dysplastic changes that were refractory to hematinic therapy. Also, she was noted to have failure to thrive, developmental delay and epilepsy. She was referred to the Genetics clinic where whole-exome sequencing (WES) was done and showed a novel homozygous variant in the gene confirming a diagnosis of HOA. She was started on uridine triacetate after which she showed clinical, hematologic and biochemical improvement. Although extremely rare, hereditary orotic aciduria should be suspected in any child with megaloblastic bone marrow, immunodeficiency or when developmental delay and anemia coexist.
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http://dx.doi.org/10.1016/j.ymgmr.2020.100703DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7807243PMC
March 2021

First 1.5 years of pegvaliase clinic: Experiences and outcomes.

Mol Genet Metab Rep 2020 Sep 25;24:100603. Epub 2020 May 25.

Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, United States of America.

We present Boston Children's Hospital's clinic model for pegvaliase therapy in adults with phenylketonuria (PKU) and clinical outcomes in 46 patients over the first 1.5 years of commercial therapy. Approximately 70% (18/26) of patients starting pegvaliase achieved blood phenylalanine (Phe) <360 μmol/L, with an average of a 68 ± 24% decrease in blood Phe from baseline. All patients experienced at least minor side effects, but in most, management of the side effects allowed for treatment to continue.
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http://dx.doi.org/10.1016/j.ymgmr.2020.100603DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7256053PMC
September 2020

Activating Mutations of RRAS2 Are a Rare Cause of Noonan Syndrome.

Am J Hum Genet 2019 06 23;104(6):1223-1232. Epub 2019 May 23.

Institute of Human Genetics, University Hospital Magdeburg, 39120 Magdeburg, Germany. Electronic address:

Aberrant signaling through pathways controlling cell response to extracellular stimuli constitutes a central theme in disorders affecting development. Signaling through RAS and the MAPK cascade controls a variety of cell decisions in response to cytokines, hormones, and growth factors, and its upregulation causes Noonan syndrome (NS), a developmental disorder whose major features include a distinctive facies, a wide spectrum of cardiac defects, short stature, variable cognitive impairment, and predisposition to malignancies. NS is genetically heterogeneous, and mutations in more than ten genes have been reported to underlie this disorder. Despite the large number of genes implicated, about 10%-20% of affected individuals with a clinical diagnosis of NS do not have mutations in known RASopathy-associated genes, indicating that additional unidentified genes contribute to the disease, when mutated. By using a mixed strategy of functional candidacy and exome sequencing, we identify RRAS2 as a gene implicated in NS in six unrelated subjects/families. We show that the NS-causing RRAS2 variants affect highly conserved residues localized around the nucleotide binding pocket of the GTPase and are predicted to variably affect diverse aspects of RRAS2 biochemical behavior, including nucleotide binding, GTP hydrolysis, and interaction with effectors. Additionally, all pathogenic variants increase activation of the MAPK cascade and variably impact cell morphology and cytoskeletal rearrangement. Finally, we provide a characterization of the clinical phenotype associated with RRAS2 mutations.
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http://dx.doi.org/10.1016/j.ajhg.2019.04.013DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6562003PMC
June 2019

Evidence- and consensus-based recommendations for the use of pegvaliase in adults with phenylketonuria.

Genet Med 2019 08 14;21(8):1851-1867. Epub 2018 Dec 14.

Departments of Molecular and Medical Genetics and Pediatrics, Oregon Health & Science University, Portland, OR, USA.

Purpose: Phenylketonuria (PKU) is a rare metabolic disorder that requires life-long management to reduce phenylalanine (Phe) concentrations within the recommended range. The availability of pegvaliase (PALYNZIQ™, an enzyme that can metabolize Phe) as a new therapy necessitates the provision of guidance for its use.

Methods: A Steering Committee comprising 17 health-care professionals with experience in using pegvaliase through the clinical development program drafted guidance statements during a series of face-to-face meetings. A modified Delphi methodology was used to demonstrate consensus among a wider group of health-care professionals with experience in using pegvaliase.

Results: Guidance statements were developed for four categories: (1) treatment goals and considerations prior to initiating therapy, (2) dosing considerations, (3) considerations for dietary management, and (4) best approaches to optimize medical management. A total of 34 guidance statements were included in the modified Delphi voting and consensus was reached on all after two rounds of voting.

Conclusion: Here we describe evidence- and consensus-based recommendations for the use of pegvaliase in adults with PKU. The manuscript was evaluated against the Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument and is intended for use by health-care professionals who will prescribe pegvaliase and those who will treat patients receiving pegvaliase.
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http://dx.doi.org/10.1038/s41436-018-0403-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6752676PMC
August 2019

Refining the phenotype associated with GNB1 mutations: Clinical data on 18 newly identified patients and review of the literature.

Am J Med Genet A 2018 11 8;176(11):2259-2275. Epub 2018 Sep 8.

Division of Clinical Genetics, Department of Pediatrics, Columbia University Medical Center (CUMC), New York, New York.

De novo germline mutations in GNB1 have been associated with a neurodevelopmental phenotype. To date, 28 patients with variants classified as pathogenic have been reported. We add 18 patients with de novo mutations to this cohort, including a patient with mosaicism for a GNB1 mutation who presented with a milder phenotype. Consistent with previous reports, developmental delay in these patients was moderate to severe, and more than half of the patients were non-ambulatory and nonverbal. The most observed substitution affects the p.Ile80 residue encoded in exon 6, with 28% of patients carrying a variant at this residue. Dystonia and growth delay were observed more frequently in patients carrying variants in this residue, suggesting a potential genotype-phenotype correlation. In the new cohort of 18 patients, 50% of males had genitourinary anomalies and 61% of patients had gastrointestinal anomalies, suggesting a possible association of these findings with variants in GNB1. In addition, cutaneous mastocytosis, reported once before in a patient with a GNB1 variant, was observed in three additional patients, providing further evidence for an association to GNB1. We will review clinical and molecular data of these new cases and all previously reported cases to further define the phenotype and establish possible genotype-phenotype correlations.
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http://dx.doi.org/10.1002/ajmg.a.40472DOI Listing
November 2018

Multiple DICER1-related tumors in a child with a large interstitial 14q32 deletion.

Genes Chromosomes Cancer 2018 05 10;57(5):223-230. Epub 2018 Feb 10.

Department of Human Genetics, McGill University, Montréal, Québec, Canada.

Germ-line interstitial deletions involving the 14q32 chromosomal region, resulting in 14q32 deletion syndrome, are rare. DICER1 is a recently described cancer-predisposition gene located at 14q32.13. We report the case of a male child with a ∼5.8 Mbp 14q32.13q32.2 germ-line deletion, which included the full DICER1 locus. We reviewed available clinical and pathological material, and conducted genetic analyses. In addition to having congenital dysmorphic features, the child developed multiple DICER1 syndrome-related tumors before age 5 y: a pediatric cystic nephroma (pCN), a ciliary body medulloepithelioma (CBME), and a small lung cyst (consistent with occult pleuropulmonary blastoma Type I/Ir cysts seen in DICER1 mutation carriers). He also developed a cerebral spindle-cell sarcoma with myogenous differentiation. Our investigations revealed that the deletion encompassed 31 protein-coding genes. In addition to the germ-line DICER1 deletion, somatic DICER1 RNase IIIb mutations were found in the CBME (c.5437G > A, p.E1813K), pCN (c.5425G > A, p.G1809R), and sarcoma (c.5125G > A, p.D1709N). The sarcoma also harbored a somatic TP53 mutation: c.844C > T, p.R282W. Additional copy number alterations were identified in the CBME and sarcoma using an OncoScan array. Among the 8 cases with molecularly-defined 14q32 deletions involving DICER1 and for whom phenotypic information is available, our patient and one other developed DICER1-related tumors. Biallelic DICER1 mutations have not previously been reported to cause cerebral sarcoma, which now may be considered a rare manifestation of the DICER1 syndrome. Our study shows that DICER1-related tumors can occur in children with 14q32 deletions and suggests surveillance for such tumors may be warranted.
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http://dx.doi.org/10.1002/gcc.22523DOI Listing
May 2018

MPV17-related mitochondrial DNA maintenance defect: New cases and review of clinical, biochemical, and molecular aspects.

Hum Mutat 2018 04 13;39(4):461-470. Epub 2018 Jan 13.

Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas.

Mitochondrial DNA (mtDNA) maintenance defects are a group of diseases caused by deficiency of proteins involved in mtDNA synthesis, mitochondrial nucleotide supply, or mitochondrial dynamics. One of the mtDNA maintenance proteins is MPV17, which is a mitochondrial inner membrane protein involved in importing deoxynucleotides into the mitochondria. In 2006, pathogenic variants in MPV17 were first reported to cause infantile-onset hepatocerebral mtDNA depletion syndrome and Navajo neurohepatopathy. To date, 75 individuals with MPV17-related mtDNA maintenance defect have been reported with 39 different MPV17 pathogenic variants. In this report, we present an additional 25 affected individuals with nine novel MPV17 pathogenic variants. We summarize the clinical features of all 100 affected individuals and review the total 48 MPV17 pathogenic variants. The vast majority of affected individuals presented with an early-onset encephalohepatopathic disease characterized by hepatic and neurological manifestations, failure to thrive, lactic acidemia, and mtDNA depletion detected mainly in liver tissue. Rarely, MPV17 deficiency can cause a late-onset neuromyopathic disease characterized by myopathy and peripheral neuropathy with no or minimal liver involvement. Approximately half of the MPV17 pathogenic variants are missense. A genotype with biallelic missense variants, in particular homozygous p.R50Q, p.P98L, and p.R41Q, can carry a relatively better prognosis.
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http://dx.doi.org/10.1002/humu.23387DOI Listing
April 2018

Characterization of a novel variant in siblings with Asparagine Synthetase Deficiency.

Mol Genet Metab 2018 03 20;123(3):317-325. Epub 2017 Dec 20.

Department of Biochemistry & Molecular Biology, Genetics Institute, University of Florida College of Medicine, 1200 Newell Drive, FL 32608, USA. Electronic address:

Asparagine Synthetase Deficiency (ASD) is a recently described inborn error of metabolism caused by bi-allelic pathogenic variants in the asparagine synthetase (ASNS) gene. ASD typically presents congenitally with microcephaly and severe, often medically refractory, epilepsy. Development is generally severely affected at birth. Tone is abnormal with axial hypotonia and progressive appendicular spasticity. Hyperekplexia has been reported. Neuroimaging typically demonstrates gyral simplification, abnormal myelination, and progressive cerebral atrophy. The present report describes two siblings from consanguineous parents with a homozygous Arg49Gln variant associated with a milder form of ASD that is characterized by later onset of symptoms. Both siblings had a period of normal development before onset of seizures, and development regression. Primary fibroblast studies of the siblings and their parents document that homozygosity for Arg49Gln blocks cell growth in the absence of extracellular asparagine. Functional studies with these cells suggest no impact of the Arg49Gln variant on basal ASNS mRNA or protein levels, nor on regulation of the gene itself. Molecular modelling of the ASNS protein structure indicates that the Arg49Gln variant lies near the substrate binding site for glutamine. Collectively, the results suggest that the Arg49Gln variant affects the enzymatic function of ASNS. The clinical, cellular, and molecular observations from these siblings expand the known phenotypic spectrum of ASD.
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http://dx.doi.org/10.1016/j.ymgme.2017.12.433DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5832599PMC
March 2018

Desmosterolosis presenting with multiple congenital anomalies.

Eur J Med Genet 2018 Mar 23;61(3):152-156. Epub 2017 Nov 23.

Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA. Electronic address:

Desmosterolosis is a rare multiple congenital anomaly syndrome caused by a defect in the enzyme 3-beta-hydroxysterol delta-24-reductase (DHCR24) in the cholesterol biosynthesis pathway. Defects in this enzyme cause increased level of the cholesterol precursor desmosterol while disrupting development of cholesterol, impacting embryogenesis. A total of 9 cases of desmosterolosis have been reported to date. We report a 20-month-old male from consanguineous parents with multiple congenital anomalies including corpus callosum hypoplasia, facial dysmorphism, cleft palate, pectus deformity, short and wide neck and distal contractures. On analysis of the regions of homozygosity found by microarray, we identified DHCR24 as a candidate gene. Sterol quantitation showed a desmosterol level of 162 μg/mL (nl: 0.82 ± 0.48). Genetic testing confirmed the diagnosis with a homozygous likely pathogenic mutation (p.Glu191Lys) in the DHCR24 gene. Our case expands the known diagnostic spectrum for Desmosterolosis. We suggest considering Desmosterolosis in the differential diagnosis of patients who present with concurrent agenesis of the corpus callosum with white matter atrophy and ventriculomegaly, retromicrognathia with or without cleft palate, hand contractures, and delay of growth and development. Children of consanguineous mattings may be at higher risk for rare recessive disorders and testing for cholesterol synthesis defect should be a consideration for affected children. Initial evaluation can be performed using sterol quantitation, followed by genetic testing.
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http://dx.doi.org/10.1016/j.ejmg.2017.11.009DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5963269PMC
March 2018

De Novo Disruption of the Proteasome Regulatory Subunit PSMD12 Causes a Syndromic Neurodevelopmental Disorder.

Am J Hum Genet 2017 Feb 26;100(2):352-363. Epub 2017 Jan 26.

Service de Génétique Médicale, CHU de Nantes, 9 quai Moncousu, 44093 Nantes Cedex 1, France. Electronic address:

Degradation of proteins by the ubiquitin-proteasome system (UPS) is an essential biological process in the development of eukaryotic organisms. Dysregulation of this mechanism leads to numerous human neurodegenerative or neurodevelopmental disorders. Through a multi-center collaboration, we identified six de novo genomic deletions and four de novo point mutations involving PSMD12, encoding the non-ATPase subunit PSMD12 (aka RPN5) of the 19S regulator of 26S proteasome complex, in unrelated individuals with intellectual disability, congenital malformations, ophthalmologic anomalies, feeding difficulties, deafness, and subtle dysmorphic facial features. We observed reduced PSMD12 levels and an accumulation of ubiquitinated proteins without any impairment of proteasome catalytic activity. Our PSMD12 loss-of-function zebrafish CRISPR/Cas9 model exhibited microcephaly, decreased convolution of the renal tubules, and abnormal craniofacial morphology. Our data support the biological importance of PSMD12 as a scaffolding subunit in proteasome function during development and neurogenesis in particular; they enable the definition of a neurodevelopmental disorder due to PSMD12 variants, expanding the phenotypic spectrum of UPS-dependent disorders.
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http://dx.doi.org/10.1016/j.ajhg.2017.01.003DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5294671PMC
February 2017

De Novo Mutations of RERE Cause a Genetic Syndrome with Features that Overlap Those Associated with Proximal 1p36 Deletions.

Am J Hum Genet 2016 May 14;98(5):963-970. Epub 2016 Apr 14.

Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA. Electronic address:

Deletions of chromosome 1p36 affect approximately 1 in 5,000 newborns and are associated with developmental delay, intellectual disability, and defects involving the brain, eye, ear, heart, and kidney. Arginine-glutamic acid dipeptide repeats (RERE) is located in the proximal 1p36 critical region. RERE is a widely-expressed nuclear receptor coregulator that positively regulates retinoic acid signaling. Animal models suggest that RERE deficiency might contribute to many of the structural and developmental birth defects and medical problems seen in individuals with 1p36 deletion syndrome, although human evidence supporting this role has been lacking. In this report, we describe ten individuals with intellectual disability, developmental delay, and/or autism spectrum disorder who carry rare and putatively damaging changes in RERE. In all cases in which both parental DNA samples were available, these changes were found to be de novo. Associated features that were recurrently seen in these individuals included hypotonia, seizures, behavioral problems, structural CNS anomalies, ophthalmologic anomalies, congenital heart defects, and genitourinary abnormalities. The spectrum of defects documented in these individuals is similar to that of a cohort of 31 individuals with isolated 1p36 deletions that include RERE and are recapitulated in RERE-deficient zebrafish and mice. Taken together, our findings suggest that mutations in RERE cause a genetic syndrome and that haploinsufficiency of RERE might be sufficient to cause many of the phenotypes associated with proximal 1p36 deletions.
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http://dx.doi.org/10.1016/j.ajhg.2016.03.002DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4863473PMC
May 2016

Frequent detection of parental consanguinity in children with developmental disorders by a combined CGH and SNP microarray.

Mol Cytogenet 2013 Sep 20;6(1):38. Epub 2013 Sep 20.

Department of Pathology and Mailman Center for Child Development, Room 7050, University of Miami Miller School of Medicine, 1601 NW 12th Avenue, Miami, FL 33136, USA.

Background: Genomic microarrays have been used as the first-tier cytogenetic diagnostic test for patients with developmental delay/intellectual disability, autism spectrum disorders and/or multiple congenital anomalies. The use of SNP arrays has revealed regions of homozygosity in the genome which can lead to identification of uniparental disomy and parental consanguinity in addition to copy number variations. Consanguinity is associated with an increased risk of birth defects and autosomal recessive disorders. However, the frequency of parental consanguinity in children with developmental disabilities is unknown, and consanguineous couples may not be identified during doctor's visit or genetic counseling without microarray.

Results: We studied 607 proband pediatric patients referred for developmental disorders using a 4 × 180 K array containing both CGH and SNP probes. Using 720, 360, 180, and 90 Mb as the expected sizes of homozygosity for an estimated coefficient of inbreeding (F) 1/4, 1/8, 1/16, 1/32, parental consanguinity was detected in 21cases (3.46%).

Conclusion: Parental consanguinity is not uncommon in children with developmental problems in our study population, and can be identified by use of a combined CGH and SNP chromosome microarray. Identification of parental consanguinity in such cases can be important for further diagnostic testing.
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http://dx.doi.org/10.1186/1755-8166-6-38DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3853444PMC
September 2013

Clinical comparison of overlapping deletions of 19p13.3.

Am J Med Genet A 2013 May;161A(5):1110-6

Laboratory Corporation of America/Dynacare, Department of Cytogenetics, Seattle, WA 98122, USA.

We present three patients with overlapping interstitial deletions of 19p13.3 identified by high resolution SNP microarray analysis. All three had a similar phenotype characterized by intellectual disability or developmental delay, structural heart abnormalities, large head relative to height and weight or macrocephaly, and minor facial anomalies. Deletion sizes ranged from 792 Kb to 1.0 Mb and included a common region arr [hg19] 19p13.3 (3,814,392-4,136,989), containing eight genes: ZFR2, ATCAY, NMRK2, DAPK3, EEF2, PIAS4, ZBTB7A, MAP2K2, and two non-coding RNA's MIR637 and SNORDU37. The patient phenotypes were compared with three previous single patient reports with similar interstitial 19p13.3 deletions and six additional patients from the DECIPHER and ISCA databases to determine if a common haploinsufficient phenotype for the region can be established.
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http://dx.doi.org/10.1002/ajmg.a.35923DOI Listing
May 2013

Three cases of isolated terminal deletion of chromosome 8p without heart defects presenting with a mild phenotype.

Am J Med Genet A 2013 Apr 12;161A(4):822-8. Epub 2013 Mar 12.

Department of Cytogenetics, Laboratory Corporation of America, Center for Molecular Biology and Pathology, Research Triangle Park, NC 27709, USA.

Individuals with isolated terminal deletions of 8p have been well described in the literature, however, molecular characterization, particularly by microarray, of the deletion in most instances is lacking. The phenotype of such individuals falls primarily into two categories: those with cardiac defects, and those without. The architecture of 8p has been demonstrated to contain two inversely oriented segmental duplications at 8p23.1, flanking the gene, GATA4. Haploinsufficiency of this gene has been implicated in cardiac defects seen in numerous individuals with terminal 8p deletion. Current microarray technologies allow for the precise elucidation of the size and gene content of the deleted region. We present three individuals with isolated terminal deletion of 8p distal to the segmental duplication telomeric to GATA4. These individuals present with a relatively mild and nonspecific phenotype including mildly dysmorphic features, developmental delay, speech delay, and early behavior issues.
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http://dx.doi.org/10.1002/ajmg.a.35699DOI Listing
April 2013

Evidence of novel fine-scale structural variation at autism spectrum disorder candidate loci.

Mol Autism 2012 Apr 2;3. Epub 2012 Apr 2.

Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, 1501 NW 10 Ave, M-860, Miami, FL 33136, USA.

Background: Autism spectrum disorders (ASD) represent a group of neurodevelopmental disorders characterized by a core set of social-communicative and behavioral impairments. Gamma-aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the brain, acting primarily via the GABA receptors (GABR). Multiple lines of evidence, including altered GABA and GABA receptor expression in autistic patients, indicate that the GABAergic system may be involved in the etiology of autism.

Methods: As copy number variations (CNVs), particularly rare and de novo CNVs, have now been implicated in ASD risk, we examined the GABA receptors and genes in related pathways for structural variation that may be associated with autism. We further extended our candidate gene set to include 19 genes and regions that had either been directly implicated in the autism literature or were directly related (via function or ancestry) to these primary candidates. For the high resolution CNV screen we employed custom-designed 244 k comparative genomic hybridization (CGH) arrays. Collectively, our probes spanned a total of 11 Mb of GABA-related and additional candidate regions with a density of approximately one probe every 200 nucleotides, allowing a theoretical resolution for detection of CNVs of approximately 1 kb or greater on average. One hundred and sixty-eight autism cases and 149 control individuals were screened for structural variants. Prioritized CNV events were confirmed using quantitative PCR, and confirmed loci were evaluated on an additional set of 170 cases and 170 control individuals that were not included in the original discovery set. Loci that remained interesting were subsequently screened via quantitative PCR on an additional set of 755 cases and 1,809 unaffected family members.

Results: Results include rare deletions in autistic individuals at JAKMIP1, NRXN1, Neuroligin4Y, OXTR, and ABAT. Common insertion/deletion polymorphisms were detected at several loci, including GABBR2 and NRXN3. Overall, statistically significant enrichment in affected vs. unaffected individuals was observed for NRXN1 deletions.

Conclusions: These results provide additional support for the role of rare structural variation in ASD.
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http://dx.doi.org/10.1186/2040-2392-3-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3352055PMC
April 2012

Familial 16q24.3 microdeletion involving ANKRD11 causes a KBG-like syndrome.

Am J Med Genet A 2012 Mar 3;158A(3):547-52. Epub 2012 Feb 3.

Dr. John T. Macdonald Department of Human Genetics, University of Miami Miller School of Medicine, Miami, Florida 33136, USA.

Haploinsufficiency of ANKRD11 encoding ankyrin repeat domain-containing protein 11 was recently reported as the cause of a syndrome due to microdeletion, characterized by intellectual disability with minor facial anomalies and short stature. Most recently, intragenic mutations of ANKRD11 were found in a cohort of patients with KBG syndrome. KBG is an autosomal dominant intellectual disability syndrome characterized by short stature, characteristic facial appearance, macrodontia, and skeletal anomalies. It remains unknown if deletion of the entire ANKRD11 causes KBG syndrome. We present a mother and child with a heterozygous 365 Kb deletion at 16q24.3 containing ANKRD11, ZNF778, and SPG7 genes. The child presented with developmental delay, facial anomalies, hand anomalies, and a congenital heart defect. The mother has short stature, facial anomalies, macrodontia, hand anomalies, and learning disability. Both individuals had many findings reported in KBG syndrome and the family met the suggested diagnostic criteria. However, typical macrodontia with fused incisors, costovertebral anomalies, and delayed bone age were not present. We conclude that microdeletions involving ANKRD11 result in a phenotype similar to that of KBG syndrome. © 2012 Wiley Periodicals, Inc.
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http://dx.doi.org/10.1002/ajmg.a.34436DOI Listing
March 2012

Copy number variants in extended autism spectrum disorder families reveal candidates potentially involved in autism risk.

PLoS One 2011 7;6(10):e26049. Epub 2011 Oct 7.

John P. Hussman Institute for Human Genomics, Miller School of Medicine, University of Miami, Miami, Florida, United States of America.

Copy number variations (CNVs) are a major cause of genetic disruption in the human genome with far more nucleotides being altered by duplications and deletions than by single nucleotide polymorphisms (SNPs). In the multifaceted etiology of autism spectrum disorders (ASDs), CNVs appear to contribute significantly to our understanding of the pathogenesis of this complex disease. A unique resource of 42 extended ASD families was genotyped for over 1 million SNPs to detect CNVs that may contribute to ASD susceptibility. Each family has at least one avuncular or cousin pair with ASD. Families were then evaluated for co-segregation of CNVs in ASD patients. We identified a total of five deletions and seven duplications in eleven families that co-segregated with ASD. Two of the CNVs overlap with regions on 7p21.3 and 15q24.1 that have been previously reported in ASD individuals and two additional CNVs on 3p26.3 and 12q24.32 occur near regions associated with schizophrenia. These findings provide further evidence for the involvement of ICA1 and NXPH1 on 7p21.3 in ASD susceptibility and highlight novel ASD candidates, including CHL1, FGFBP3 and POUF41. These studies highlight the power of using extended families for gene discovery in traits with a complex etiology.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0026049PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3189231PMC
February 2012

A novel sporadic 614-Kb duplication of the 22q11.2 chromosome in a child with amyoplasia.

J Child Neurol 2011 Aug 13;26(8):1005-8. Epub 2011 May 13.

Department of Neurology, Leonard M. Miller School of Medicine, University of Miami, Miami, Florida 33136, USA.

Arthrogryposis is a rare congenital disorder characterized by multiple fixed joint contractures. Decreased fetal movement, regardless of etiology, causes an immobilization of the affected joints and subsequent contractures. Amyoplasia refers to the most common variant of arthrogryposis in which patients develop symmetrical limb contractures because of muscle underdevelopment. It is a sporadic condition with no known genetic abnormality being linked to this syndrome. The authors report a 4-month-old boy with amyoplasia carrying a novel de novo 614-Kb duplication of the 22q11.2 region. Amyoplasia has not been reported in patients with 22q11.2 microduplication syndrome. This particular 614-Kb duplicated segment contains 7 genes located within the typical 22q11.2 duplication region and 2 genes, TUBA8 and USP18, mapping outside of the typical region. This patient broadens the phenotypic spectrum of the 22q11.2 microduplication syndrome and raises the possibility that TUBA8 and USP18 may play an important role in the pathogenesis of amyoplasia.
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http://dx.doi.org/10.1177/0883073810394846DOI Listing
August 2011

Microduplications in an autism multiplex family narrow the region of susceptibility for developmental disorders on 15q24 and implicate 7p21.

Am J Med Genet B Neuropsychiatr Genet 2011 Jun 7;156B(4):493-501. Epub 2011 Apr 7.

John P. Hussman Institute for Human Genomics, Miller School of Medicine, University of Miami, Florida, USA.

Copy number variations (CNVs) play a crucial role in the intricate genetics of autism spectrum disorders. A region on chromosome 15q24 vulnerable to both deletions and duplications has been previously implicated in a range of phenotypes including autism, Asperger's syndrome, delayed development, and mild to severe mental retardation. Prior studies have delineated a minimal critical region of approximately 1.33 Mb. In this study, a multiplex autism family was evaluated for CNVs using genotyping data from the Illumina 1 M BeadChip and analyzed with the PennCNV algorithm. Variants were then identified that co-segregate with autism features in this family. Here, we report autistic first cousins who carry two microduplications concordant with disease. Both duplications were inherited maternally and found to be identical by descent. The first is an approximately 10,000 base pair microduplication within the minimal region on 15q24 that falls across a single gene, ubiquitin-like 7. This is the smallest duplication in the region to result in a neuropsychiatric disorder, potentially narrowing the critical region for susceptibility to developmental and autism spectrum disorders. The second is a novel, 352 kb tandem duplication on 7p21 that replicates part of the neurexophilin 1 and islet cell autoantigen 1 genes. The breakpoint junction falls within the intronic regions of these genes and demonstrates a microhomology of four base pairs. Each of these microduplications may contribute to the complex etiology of autism spectrum disorders.
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http://dx.doi.org/10.1002/ajmg.b.31188DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5490366PMC
June 2011

A de novo 1.5 Mb microdeletion on chromosome 14q23.2-23.3 in a patient with autism and spherocytosis.

Autism Res 2011 Jun 28;4(3):221-7. Epub 2011 Feb 28.

John P. Hussman Institute for Human Genomics, University of Miami, Miami, Florida 33136, USA.

Autism is a neuro-developmental disorder characterized by deficits in social interaction and communication as well as restricted interests or repetitive behaviors. Cytogenetic studies have implicated large chromosomal aberrations in the etiology of approximately 5-7% of autism patients, and the recent advent of array-based techniques allows the exploration of submicroscopic copy number variations (CNVs). We genotyped a 14-year-old boy with autism, spherocytosis and other physical dysmorphia, his parents, and two non-autistic siblings with the Illumina Human 1M Beadchip as part of a study of the molecular genetics of autism and determined copy number variants using the PennCNV algorithm. We identified and validated a de novo 1.5 Mb microdeletion of 14q23.2-23.3 in our autistic patient. This region contains 15 genes, including spectrin beta (SPTB), encoding a cytoskeletal protein previously associated with spherocytosis, methylenetetrahydrofolate dehydrogenase 1 (MTHFD1), a folate metabolizing enzyme previously associated with bipoloar disorder and schizophrenia, pleckstrin homology domain-containing family G member 3 (PLEKHG3), a guanide nucleotide exchange enriched in the brain, and churchill domain containing protein 1 (CHURC1), homologs of which regulate neuronal development in model organisms. While a similar deletion has previously been reported in a family with spherocytosis, severe learning disabilities, and mild mental retardation, this is the first implication of chr14q23.2-23.3 in the etiology of autism and points to MTHFD1, PLEKHG3, and CHURC1 as potential candidate genes contributing to autism risk.
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http://dx.doi.org/10.1002/aur.186DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3110642PMC
June 2011

Expanded newborn screening in Puerto Rico and the US Virgin Islands: education and barriers assessment.

Genet Med 2009 Mar;11(3):169-75

Cardiovascular Division, Miller School of Medicine, University of Miami, 1120 NW 14th Street, Miami, FL 33136, USA.

Purpose: The implementation of the expanded newborn screening panel of 29 disorders recommended by the American College of Medical Genetics in Puerto Rico and United States Virgin Islands is still in development or in early stages. Efforts in the territories are complicated by educational and resource barriers that generate a wide gap between the islands and the US mainland.

Methods: To meet immediate educational needs, we conducted in-services for local newborn screening professionals. The efficacy of the educational intervention was measured by pre and posttest scores and a seminar evaluation. An assessment was obtained to document local newborn screening needs and barriers, with focus on human resources, intervention, language, social issues, education, and communication.

Results: Statistical significance was found (P value < or =0.05) between pre and posttest scores of the educational intervention. Needs and barriers associated with expanded newborn screening were also documented.

Conclusion: Puerto Rico and United States Virgin Islands face different challenges in their implementation of expanded newborn screening. The data obtained in the present study serves as foundation for the development of public policy and long-term educational programs.
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http://dx.doi.org/10.1097/GIM.0b013e318193076fDOI Listing
March 2009

Detection of pathogenic gene copy number variations in patients with mental retardation by genomewide oligonucleotide array comparative genomic hybridization.

Hum Mutat 2007 Nov;28(11):1124-32

The Dr. John T. Macdonald Foundation Center for Medical Genetics, University of Miami Miller School of Medicine, Miami, Florida, USA.

Genomic imbalance is a major cause of developmental disorders. Microarray-based comparative genomic hybridization (aCGH) has revealed frequent imbalances associated with clinical syndromes, but also a large number of copy number variations (CNVs), which have complicated the interpretation of results. We studied 100 consecutive patients with unexplained mental retardation and a normal karyotype using several platforms of CGH arrays. A genomewide array with 44,290 oligonucleotide probes (OaCGH44K) detected imbalances in 15% of cases studied with sizes ranged from 459 kb to 19 Mb while revealing a small number of CNVs (0.72/individual). Another platform with approximately 240,000 oligonucleotide probes (OaCGH244K) revealed a large number of CNVs (20/individual) in selected cases and their normal parents. We used a comprehensive approach for interpreting the results of aCGH, including consideration of the size, inheritance and gene content of CNVs, and consultation with an online Database of Genomic Variants (DGV) and Online Mendelian Inheritance in Men (OMIM) for information on the genes involved. Our study suggests that genomewide oligonucleotide arrays such as the OaCGH44K platform can be used as a powerful diagnostic tool for detection of genomic imbalances associated with unexplained mental retardation or syndromic autism spectrum disorders. It is interesting to note that a small number of common variants were revealed by OaCGH244K in some study subjects but not in their parents and that some inherited CNVs had altered breakpoints. Further investigations on these alterations may provide useful information for understanding the mechanism of CNVs.
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http://dx.doi.org/10.1002/humu.20581DOI Listing
November 2007