@article {886, title = {Community-based recruitment and exome sequencing indicates high diagnostic yield in adults with intellectual disability.}, journal = {Mol Genet Genomic Med}, volume = {8}, year = {2020}, month = {2020 10}, pages = {e1439}, abstract = {

BACKGROUND: Establishing a genetic diagnosis for individuals with intellectual disability (ID) benefits patients and their families as it may inform the prognosis, lead to appropriate therapy, and facilitate access to medical and supportive services. Exome sequencing has been successfully applied in a diagnostic setting, but most clinical exome referrals are pediatric patients, with many adults with ID lacking a comprehensive genetic evaluation.

METHODS: Our unique recruitment strategy involved partnering with service and education providers for individuals with ID. We performed exome sequencing and analysis, and clinical variant interpretation for each recruited family.

RESULTS: All five families enrolled in the study opted-in for the return of genetic results. In three out of five families exome sequencing analysis identified pathogenic or likely pathogenic variants in KANSL1, TUSC3, and MED13L genes. Families discussed the results and any potential medical follow-up in an appointment with a board certified clinical geneticist.

CONCLUSION: Our study suggests high yield of exome sequencing as a diagnostic tool in adult patients with ID who have not undergone comprehensive sequencing-based genetic testing. Research studies including an option of return of results through a genetic clinic could help minimize the disparity in exome diagnostic testing between pediatric and adult patients with ID.

}, keywords = {Adult, Female, Genetic Testing, Humans, Independent Living, Intellectual Disability, Male, Mediator Complex, Membrane Proteins, Nuclear Proteins, Patient Selection, Sensitivity and Specificity, Tumor Suppressor Proteins, Whole Exome Sequencing}, issn = {2324-9269}, doi = {10.1002/mgg3.1439}, author = {Sabo, Aniko and Murdock, David and Dugan, Shannon and Meng, Qingchang and Gingras, Marie-Claude and Hu, Jianhong and Muzny, Donna and Gibbs, Richard} } @article {712, title = {A diagnostic ceiling for exome sequencing in cerebellar ataxia and related neurological disorders.}, journal = {Hum Mutat}, volume = {41}, year = {2020}, month = {2020 02}, pages = {487-501}, abstract = {

Genetic ataxias are associated with mutations in hundreds of genes with high phenotypic overlap complicating the clinical diagnosis. Whole-exome sequencing (WES) has increased the overall diagnostic rate considerably. However, the upper limit of this method remains ill-defined, hindering efforts to address the remaining diagnostic gap. To further assess the role of rare coding variation in ataxic disorders, we reanalyzed our previously published exome cohort of 76 predominantly adult and sporadic-onset patients, expanded the total number of cases to 260, and introduced analyses for copy number variation and repeat expansion in a representative subset. For new cases (n = 184), our resulting clinically relevant detection rate remained stable at 47\% with 24\% classified as pathogenic. Reanalysis of the previously sequenced 76 patients modestly improved the pathogenic rate by 7\%. For the combined cohort (n = 260), the total observed clinical detection rate was 52\% with 25\% classified as pathogenic. Published studies of similar neurological phenotypes report comparable rates. This consistency across multiple cohorts suggests that, despite continued technical and analytical advancements, an approximately 50\% diagnostic rate marks a relative ceiling for current WES-based methods and a more comprehensive genome-wide assessment is needed to identify the missing causative genetic etiologies for cerebellar ataxia and related neurodegenerative diseases.

}, issn = {1098-1004}, doi = {10.1002/humu.23946}, author = {Ngo, Kathie J and Rexach, Jessica E and Lee, Hane and Petty, Lauren E and Perlman, Susan and Valera, Juliana M and Deignan, Joshua L and Mao, Yuanming and Aker, Mamdouh and Posey, Jennifer E and Jhangiani, Shalini N and Coban-Akdemir, Zeynep H and Boerwinkle, Eric and Muzny, Donna and Nelson, Alexandra B and Hassin-Baer, Sharon and Poke, Gemma and Neas, Katherine and Geschwind, Michael D and Grody, Wayne W and Gibbs, Richard and Geschwind, Daniel H and Lupski, James R and Below, Jennifer E and Nelson, Stanley F and Fogel, Brent L} } @article {947, title = {Whole exome sequencing in a large pedigree with DCM identifies a novel mutation in .}, journal = {Acta Cardiol}, volume = {75}, year = {2020}, month = {2020 Dec}, pages = {748-753}, abstract = {

Familial dilated cardiomyopathy (DCM) is genetically heterogeneous and is associated with mutations in at least 40 different genes. Apart from encoding the giant protein Titin, none of these genes have an expected diagnostic yield of more than 5\% complicating genetic diagnosis. Whole exome sequencing (WES) is a powerful alternative for the identification of the causal gene, however variant interpretation remains challenging. We report on WES in a large family with autosomal dominant DCM complicated by end stage heart failure and non-sustained ventricular arrhythmias in whom no causative mutation was identified using a targeted gene panel including 28 genes. WES was applied on 2 affected cousins. Stringent filtering of the identified genetic variants was performed including population variant frequencies, in silico analysis, orthologous and paralogous conservation. Subsequently Sanger sequencing was performed for 10 potential disease causing variants in order to confirm the presence of the variant and to evaluate co-segregation. Only one variant in exon 9 of the RBM20 gene (c.2714T > A, p.Met950Lys, NM_001334363) showed full co-segregation in the 7 affected family members resulting in a maximum 2-point LOD score of 2.1 and suggesting this as the pathogenic mutation responsible for the phenotype. Recently mutations in RBM20 have been linked to arrhythmogenic dilated cardiomyopathy caused by defective splicing of the giant sarcomere protein titin and abnormal calcium handling. We report the identification of a novel mutation in RBM20 by WES in a large pedigree with DCM.

}, issn = {1784-973X}, doi = {10.1080/00015385.2019.1674490}, author = {Robyns, Tomas and Willems, Rik and Van Cleemput, Johan and Jhangiani, Shalini and Muzny, Donna and Gibbs, Richard and Lupski, James R and Breckpot, Jeroen and Devriendt, Koenraad and Corveleyn, Anniek} } @article {353, title = {Corner fracture type spondylometaphyseal dysplasia: Overlap with type II collagenopathies.}, journal = {Am J Med Genet A}, volume = {173}, year = {2017}, month = {2017 Mar}, pages = {733-739}, abstract = {

Spondylometaphyseal dysplasia (SMD) corner fracture type (also known as SMD "Sutcliffe" type, MIM 184255) is a rare skeletal dysplasia that presents with mild to moderate short stature, developmental coxa vara, mild platyspondyly, corner fracture-like lesions, and metaphyseal abnormalities with sparing of the epiphyses. The molecular basis for this disorder has yet to be clarified. We describe two patients with SMD corner fracture type and heterozygous pathogenic variants in COL2A1. These two cases together with a third case of SMD corner fracture type with a heterozygous COL2A1 pathogenic variant previously described suggest that this disorder overlaps with type II collagenopathies. The finding of one of the pathogenic variants in a previously reported case of spondyloepimetaphyseal dysplasia (SEMD) Strudwick type and the significant clinical similarity suggest an overlap between SMD corner fracture and SEMD Strudwick types. {\textcopyright} 2016 Wiley Periodicals, Inc.

}, keywords = {Alleles, Amino Acid Substitution, Bone Diseases, Developmental, Child, Preschool, Collagen Type II, Diagnosis, Differential, Exome, Genetic Association Studies, Genotype, Growth Disorders, High-Throughput Nucleotide Sequencing, Hip Joint, Humans, Infant, Male, Mutation, Osteochondrodysplasias, Phenotype, Radiography, Tibial Fractures}, issn = {1552-4833}, doi = {10.1002/ajmg.a.38059}, author = {Machol, Keren and Jain, Mahim and Almannai, Mohammed and Orand, Thibault and Lu, James T and Tran, Alyssa and Chen, Yuqing and Schlesinger, Alan and Gibbs, Richard and Bonafe, Luisa and Campos-Xavier, Ana Belinda and Unger, Sheila and Superti-Furga, Andrea and Lee, Brendan H and Campeau, Philippe M and Burrage, Lindsay C} } @article {140, title = {Phenotypic Expansion of Congenital Disorder of Glycosylation Due to SRD5A3 Null Mutation.}, journal = {JIMD Rep}, volume = {26}, year = {2016}, month = {2016}, pages = {7-12}, abstract = {

We present a boy, admitted at 4 months, with facial dysmorphism, hypertrichosis, loose skin, bilateral inguinal hernia, severe hypotonia, psychomotor disability, seizures with hypsarrhythmia (West syndrome), hepatosplenomegaly, increased serum transaminases, iris coloboma, glaucoma, corneal clouding and bilateral dilated lateral ventricles, and extra-axial post-cerebellar space. Serum transferrin isoelectrofocusing (IEF) showed a type 1 pattern. Whole-exome genotyping showed a previously reported homozygous nonsense mutation c.320G>A; p.Trp107X in SRD5A3. Epilepsy and glaucoma have been reported only once in the 19 described SRD5A3-congenital glycosylation defect patients, and corneal clouding not at all.

}, issn = {2192-8304}, doi = {10.1007/8904_2015_478}, author = {Tuysuz, Beyhan and Pehlivan, Davut and {\"O}zk{\"o}k, Ahmet and Jhangiani, Shalini and Yalcinkaya, Cengiz and Zeybek, {\c C}i{\u g}dem Aktu{\u g}lu and Muzny, Donna Marie and Lupski, James R and Gibbs, Richard and Jaeken, Jaak} } @article {197, title = {Association of Rare Loss-Of-Function Alleles in HAL, Serum Histidine: Levels and Incident Coronary Heart Disease.}, journal = {Circ Cardiovasc Genet}, volume = {8}, year = {2015}, month = {2015 Apr}, pages = {351-5}, abstract = {

BACKGROUND: Histidine is a semiessential amino acid with antioxidant and anti-inflammatory properties. Few data are available on the associations between genetic variants, histidine levels, and incident coronary heart disease (CHD) in a population-based sample.

METHODS AND RESULTS: By conducting whole exome sequencing on 1152 African Americans in the Atherosclerosis Risk in Communities (ARIC) study and focusing on loss-of-function (LoF) variants, we identified 3 novel rare LoF variants in HAL, a gene that encodes histidine ammonia-lyase in the first step of histidine catabolism. These LoF variants had large effects on blood histidine levels (β=0.26; P=1.2{\texttimes}10(-13)). The positive association with histidine levels was replicated by genotyping an independent sample of 718 ARIC African Americans (minor allele frequency=1\%; P=1.2{\texttimes}10(-4)). In addition, high blood histidine levels were associated with reduced risk of developing incident CHD with an average of 21.5 years of follow-up among African Americans (hazard ratio=0.18; P=1.9{\texttimes}10(-4)). This finding was validated in an independent sample of European Americans from the Framingham Heart Study (FHS) Offspring Cohort. However, LoF variants in HAL were not directly significantly associated with incident CHD after meta-analyzing results from the CHARGE Consortium.

CONCLUSIONS: Three LoF mutations in HAL were associated with increased histidine levels, which in turn were shown to be inversely related to the risk of CHD among both African Americans and European Americans. Future investigations on the association between HAL gene variation and CHD are warranted.

}, keywords = {Adult, African Americans, Alleles, Coronary Disease, European Continental Ancestry Group, Female, Histidine, Histidine Ammonia-Lyase, Humans, Male, Mutation}, issn = {1942-3268}, doi = {10.1161/CIRCGENETICS.114.000697}, author = {Yu, Bing and Li, Alexander H and Muzny, Donna and Veeraraghavan, Narayanan and de Vries, Paul S and Bis, Joshua C and Musani, Solomon K and Alexander, Danny and Morrison, Alanna C and Franco, Oscar H and Uitterlinden, Andr{\'e} and Hofman, Albert and Dehghan, Abbas and Wilson, James G and Psaty, Bruce M and Gibbs, Richard and Wei, Peng and Boerwinkle, Eric} } @article {216, title = {New mutations in the RAB28 gene in 2 Spanish families with cone-rod dystrophy.}, journal = {JAMA Ophthalmol}, volume = {133}, year = {2015}, month = {2015 Feb}, pages = {133-9}, abstract = {

IMPORTANCE: The families evaluated in this study represent the second report of cone-rod dystrophy (CRD) cases caused by mutations in RAB28, a recently discovered gene associated with CRD.

OBJECTIVE: To determine the disease-causing gene in 2 families of Spanish descent presenting with CRD who do not have ABCA4 mutations.

DESIGN, SETTING, AND PARTICIPANTS: Molecular genetics and observational case studies of 2 families, each with 1 affected proband with CRD and 3 or 5 unaffected family members. The affected individual from each family received a complete ophthalmic examination including assessment of refractive errors and best-corrected visual acuity, biomicroscopy, color fundus photography, electroretinography analysis, and visual-evoked potential analysis. After complete sequencing of the ABCA4 gene with negative results, the screening for disease-causing mutations was performed by whole-exome sequencing. Possible disease-associated variants were determined by filtering based on minor allele frequency, predicted pathogenicity, and segregation analysis in all family members.

MAIN OUTCOMES AND MEASURES: The appearance of the macula was evaluated by clinical examination, fundus photography, and fundus autofluorescence imaging, and visual function was assessed by electroretinography. Disease-causing mutations were assessed by sequence analyses.

RESULTS: Ophthalmologic findings included markedly reduced visual acuity, bull{\textquoteright}s eye maculopathy, foveal hyperpigmentation, peripapillary atrophy, dyschromatopsia, extinguished photopic responses, and reduced scotopic responses observed on electroretinography consistent with the CRD phenotype often associated with ABCA4 mutations. Although no ABCA4 mutations were detected in either patient, whole-exome sequencing analysis identified 2 new homozygous mutations in the recently described RAB28 gene, the c.172 + 1G>C splice site variant in IVS2 and the missense c.T651G:p.C217W substitution. Both variants were determined as deleterious by predictive programs and were segregated with the disease in both families. Sequencing of 107 additional patients of Spanish descent with CRD did not reveal other cases with RAB28 mutations.

CONCLUSIONS AND RELEVANCE: Deleterious mutations in RAB28 result in a classic CRD phenotype and are an infrequent cause of CRD in the Spanish population.

}, keywords = {Adolescent, Adult, Child, Diagnosis, Differential, DNA Mutational Analysis, Female, Follow-Up Studies, Genetic Predisposition to Disease, Hispanic Americans, Humans, Male, Microscopy, Acoustic, Mutation, Pedigree, Phenotype, rab GTP-Binding Proteins, Retinitis Pigmentosa, Retrospective Studies, Young Adult}, issn = {2168-6173}, doi = {10.1001/jamaophthalmol.2014.4266}, author = {Riveiro-{\'A}lvarez, Rosa and Xie, Yajing Angela and L{\'o}pez-Mart{\'\i}nez, Miguel-{\'A}ngel and Gambin, Tomasz and P{\'e}rez-Carro, Raquel and {\'A}vila-Fern{\'a}ndez, Almudena and L{\'o}pez-Molina, Mar{\'\i}a-Isabel and Zernant, Jana and Jhangiani, Shalini and Muzny, Donna and Yuan, Bo and Boerwinkle, Eric and Gibbs, Richard and Lupski, James R and Ayuso, Carmen and Allikmets, Rando} } @article {192, title = {Whole Exome Sequencing Identifies an Adult-Onset Case of Methylmalonic Aciduria and Homocystinuria Type C (cblC) with Non-Syndromic Bull{\textquoteright}s Eye Maculopathy.}, journal = {Ophthalmic Genet}, volume = {36}, year = {2015}, month = {2015}, pages = {270-5}, abstract = {

BACKGROUND: Methylmalonic aciduria and homocystinuria type C (cblC), a disorder of vitamin B12 (cobalamin) metabolism caused by mutations in the MMACHC gene, presents with many systemic symptoms, including neurological, cognitive, psychiatric, and thromboembolic events. Retinal phenotypes, including maculopathy, pigmentary retinopathy, and optic atrophy are common in early onset form of the disease but are rare in adult onset forms.

MATERIALS AND METHODS: An adult Hispanic female presented with decreased central vision, bilateral pericentral ring scotomas and bull{\textquoteright}s eye-appearing macular lesions at 28 years of age. Her medical history was otherwise unremarkable except for iron deficiency anemia and both urinary tract and kidney infections. Screening of the ABCA4 gene, mutations in which frequently cause bull{\textquoteright}s eye maculopathy, was negative. Subsequently, analysis with whole exome sequencing was performed.

RESULTS: Whole exome sequencing discovered compound heterozygous mutations in MMACHC, c.G482A:p.Arg161Gln and c.270_271insA:p.Arg91Lysfs*14, which segregated with the disease in the family. The genetic diagnosis was confirmed by biochemical laboratory testing, showing highly elevated urine methylmalonic acid/creatinine and homocysteine levels, and suggesting disease management with hydroxycobalamin injections and carnitine supplementation.

CONCLUSIONS: In summary, a unique case of an adult patient with bull{\textquoteright}s eye macular lesions and no clinically relevant systemic symptoms was diagnosed with cblC by genetic screening and follow-up biochemical laboratory tests.

}, keywords = {Adult, Carrier Proteins, Electroretinography, Exome, Female, Genetic Testing, Heterozygote, Homocystinuria, Humans, Macular Degeneration, Mutation, Pedigree, Scotoma, Sequence Analysis, DNA, Tomography, Optical Coherence, Visual Acuity, Visual Fields, Vitamin B 12, Vitamin B 12 Deficiency, Vitamin B Complex}, issn = {1744-5094}, doi = {10.3109/13816810.2015.1010736}, author = {Collison, Frederick T and Xie, Yajing Angela and Gambin, Tomasz and Jhangiani, Shalini and Muzny, Donna and Gibbs, Richard and Lupski, James R and Fishman, Gerald A and Allikmets, Rando} } @article {242, title = {New syndrome with retinitis pigmentosa is caused by nonsense mutations in retinol dehydrogenase RDH11.}, journal = {Hum Mol Genet}, volume = {23}, year = {2014}, month = {2014 Nov 01}, pages = {5774-80}, abstract = {

Retinitis pigmentosa (RP), a genetically heterogeneous group of retinopathies that occur in both non-syndromic and syndromic forms, is caused by mutations in \~{}100 genes. Although recent advances in next-generation sequencing have aided in the discovery of novel RP genes, a number of the underlying contributing genes and loci remain to be identified. We investigated three siblings, born to asymptomatic parents of Italian-American descent, who each presented with atypical RP with systemic features, including facial dysmorphologies, psychomotor developmental delays recognized since early childhood, learning disabilities and short stature. RP-associated ophthalmological findings included salt-and-pepper retinopathy, attenuation of the arterioles and generalized rod-cone dysfunction as determined by almost extinguished electroretinogram in 2 of 3 siblings. Atypical for RP features included mottled macula at an early age and peripapillary sparing of the retinal pigment epithelium. Whole-exome sequencing data, queried under a recessive model of inheritance, identified compound heterozygous stop mutations, c.C199T:p.R67* and c.C322T:p.R108*, in the retinol dehydrogenase 11 (RDH11) gene, resulting in a non-functional protein, in all affected children. In summary, deleterious mutations in RDH11, an important enzyme for vision-related and systemic retinoic acid metabolism, cause a new syndrome with RP.

}, keywords = {Adolescent, Child, Codon, Nonsense, Female, Humans, Male, Oxidoreductases, Pedigree, Phenotype, Retinitis Pigmentosa, Syndrome, Vision Tests, Visual Acuity, Young Adult}, issn = {1460-2083}, doi = {10.1093/hmg/ddu291}, author = {Xie, Yajing Angela and Lee, Winston and Cai, Carolyn and Gambin, Tomasz and N{\~o}upuu, Kalev and Sujirakul, Tharikarn and Ayuso, Carmen and Jhangiani, Shalini and Muzny, Donna and Boerwinkle, Eric and Gibbs, Richard and Greenstein, Vivienne C and Lupski, James R and Tsang, Stephen H and Allikmets, Rando} }