Prevalence of RFC1-Mediated Spinocerebellar Ataxia in a United States Ataxia Cohort

ABSTRACTObjectiveRepeat expansions in RFC1 and DAB1 have recently been identified as causing cerebellar ataxia, neuropathy, and vestibular areflexia syndrome (CANVAS) and spinocerebellar ataxia 37 (SCA37), respectively. We evaluated the prevalence of these repeat-expansions in an undiagnosed ataxia cohort from the United States.MethodsA cohort of 596 patients with undiagnosed familial or sporadic cerebellar ataxia were evaluated at a tertiary referral ataxia center and excluded for common genetic causes of cerebellar ataxia. Patients were then screened for the presence of pathogenic repeat expansions in RFC1 (AAGGG) and DAB1 (ATTTC) using fluorescent repeat primed polymerase chain reaction (RP-PCR). Two additional undiagnosed ataxia cohorts from different centers, totaling 96 and 13 patients respectively, were subsequently screened for RFC1 resulting in a combined 705 subjects tested.ResultsIn the initial cohort, 42 samples were identified with one expanded allele in the RFC1 gene (7.0%), and 9 had two expanded alleles (1.5%). For the additional cohorts, we found 12 heterozygous samples (12.5%) and 7 biallelic samples (7.3%) in the larger cohort, and 1 heterozygous sample (7.7%) and 3 biallelic samples (23%) in the second. In total, 19 patients were identified with biallelic repeat expansions in RFC1 (2.7%). Of these 19 patients, 6 (32%) had a clinical diagnosis of CANVAS, 10 had cerebellar ataxia with neuropathy (53%), and 3 had spinocerebellar ataxia (16%). No patients were identified with expansions in the DAB1 gene.ConclusionIn a large undiagnosed ataxia cohort from the United States, biallelic pathogenic repeat expansion in RFC1 was observed in 2.7%. Testing should be strongly considered in ataxia patients, especially those with CANVAS or neuropathy.

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Prevalence of RFC1-mediated spinocerebellar ataxia in a North American ataxia cohort

Neurology Genetics ◽

10.1212/nxg.0000000000000440 ◽

2020 ◽

Vol 6 (3) ◽

pp. e440 ◽

Cited By ~ 1

Author(s):

Dona Aboud Syriani ◽

Darice Wong ◽

Sameer Andani ◽

Claudio M. De Gusmao ◽

Yuanming Mao ◽

...

Keyword(s):

North America ◽

Cerebellar Ataxia ◽

Spinocerebellar Ataxia ◽

Adaptor Protein ◽

Spinocerebellar Ataxia Type ◽

Initial Cohort ◽

C Subunit ◽

Heterozygous Sample ◽

Repeat Expansions ◽

Factor C

ObjectiveWe evaluated the prevalence of pathogenic repeat expansions in replication factor C subunit 1 (RFC1) and disabled adaptor protein 1 (DAB1) in an undiagnosed ataxia cohort from North America.MethodsA cohort of 596 predominantly adult-onset patients with undiagnosed familial or sporadic cerebellar ataxia was evaluated at a tertiary referral ataxia center and excluded for common genetic causes of cerebellar ataxia. Patients were then screened for the presence of pathogenic repeat expansions in RFC1 (AAGGG) and DAB1 (ATTTC) using fluorescent repeat-primed PCR (RP-PCR). Two additional undiagnosed ataxia cohorts from different centers, totaling 302 and 13 patients, respectively, were subsequently screened for RFC1, resulting in a combined 911 subjects tested.ResultsIn the initial cohort, 41 samples were identified with 1 expanded allele in the RFC1 gene (6.9%), and 9 had 2 expanded alleles (1.5%). For the additional cohorts, we found 20 heterozygous samples (6.6%) and 17 biallelic samples (5.6%) in the larger cohort and 1 heterozygous sample (7.7%) and 3 biallelic samples (23%) in the second. In total, 29 patients were identified with biallelic repeat expansions in RFC1 (3.2%). Of these 29 patients, 8 (28%) had a clinical diagnosis of cerebellar ataxia, neuropathy, and vestibular areflexia syndrome (CANVAS), 14 had cerebellar ataxia with neuropathy (48%), 4 had pure cerebellar ataxia (14%), and 3 had spinocerebellar ataxia (10%). No patients were identified with expansions in the DAB1 gene (spinocerebellar ataxia type 37).ConclusionsIn a large undiagnosed ataxia cohort from North America, biallelic pathogenic repeat expansion in RFC1 was observed in 3.2%. Testing should be strongly considered in patients with ataxia, especially those with CANVAS or neuropathy.

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Transmission of the Citrus Variegated Chlorosis Bacterium Xylella fastidiosa with the Sharpshooter Oncometopia nigricans

Plant Disease ◽

10.1094/pdis.2002.86.11.1237 ◽

2002 ◽

Vol 86 (11) ◽

pp. 1237-1239 ◽

Cited By ~ 15

Author(s):

R. H. Brlansky ◽

V. D. Damsteegt ◽

J. S. Hartung

Keyword(s):

United States ◽

Polymerase Chain Reaction ◽

Xylella Fastidiosa ◽

The United States ◽

Reliable Indicator ◽

Symptom Development ◽

Chain Reaction ◽

Citrus Variegated Chlorosis ◽

Specific Polymerase Chain Reaction ◽

Polymerase Chain

Citrus variegated chlorosis (CVC) is an economically important, destructive disease in Brazil and is caused by the bacterium Xylella fastidiosa Wells. The bacterium has been found to be transmitted in Brazil by sharpshooter leafhoppers (Cicadellidae). Sharpshooters are present in most citrus growing areas of the United States. The sharpshooter leafhopper, Oncometopia nigricans Walker, frequently is found feeding on citrus in Florida. This sharpshooter transmits the X. fastidiosa strains that cause Pierce's disease of grape and ragweed stunt. Research was initiated to determine if O. nigricans was capable of vectoring the X. fastidiosa that causes CVC. In 59 different transmission tests, using 1 to 57 insects per test, transmission of the bacterium was observed 12 times (20.3%). Symptom development in the greenhouse was not a reliable indicator of transmission. Transmission was verified by specific polymerase chain reaction-based assays. Individual insects were able to transmit the bacterium. This information on sharpshooter transmission of CVC is needed to assess the threat posed by the CVC disease to the citrus industries in the United States.

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The use of quantitative polymerase chain reaction for the detection and enumeration of the harmful algaAureococcus anophagefferensin environmental samples along the United States East Coast

Limnology and Oceanography Methods ◽

10.4319/lom.2003.1.92 ◽

2003 ◽

Vol 1 (1) ◽

pp. 92-102 ◽

Cited By ~ 21

Author(s):

Linda C. Popels ◽

S. Craig Cary ◽

David A. Hutchins ◽

Rachel Forbes ◽

Frances Pustizzi ◽

...

Keyword(s):

United States ◽

Polymerase Chain Reaction ◽

Environmental Samples ◽

East Coast ◽

Quantitative Polymerase Chain Reaction ◽

The United States ◽

Chain Reaction ◽

Polymerase Chain

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Occurrence of Canine Parvovirus Type 2c in the United States

Journal of Veterinary Diagnostic Investigation ◽

10.1177/104063870701900512 ◽

2007 ◽

Vol 19 (5) ◽

pp. 535-539 ◽

Cited By ~ 105

Author(s):

Charles Hong ◽

Nicola Decaro ◽

Costantina Desario ◽

Patrick Tanner ◽

M. Camila Pardo ◽

...

Keyword(s):

United States ◽

Antigenic Site ◽

The United States ◽

Canine Parvovirus ◽

Single Nucleotide ◽

Diagnostic Assays ◽

New Variant ◽

Taqman Pcr ◽

Polymerase Chain

Canine parvovirus (CPV) type 2 (CPV-2) emerged around 1978 as a major pathogen of dogs worldwide. In the mid-1980s, the original CPV-2 had evolved and was completely replaced by 2 variants, CPV-2a and CPV-2b. In 2000, a new variant of CPV (named CPV-2c) was detected in Italy and now cocirculates with types 2a and 2b in that country. The CPV-2c has also been reported from single outbreaks in Vietnam and Spain. This study was conducted to determine if CPV-2c occurs in the United States. Thirty-three fecal samples were collected from dogs in 16 states between April 2006 and April 2007 and were tested for CPV using real-time polymerase chain reaction (PCR). Positive samples were further tested using conventional PCR and minor-groove binding TaqMan PCR assays to determine the viral type and to differentiate vaccine strains from field strains. Twenty-seven samples were positive for CPV, 7 of which were CPV-2c from 5 states: Arizona, California, Georgia, Oklahoma, and Texas. Of the 7 isolates, 4 differed from European CPV-2c isolates by 2 additional single-nucleotide mutations at positions 4076 and 4104, the latter of which produces a ThrAla change at residue 440 located near a major antigenic site. The coast-to-coast geographic distribution of the states in which CPV-2c was detected strongly suggests that this new CPV variant is probably widespread in the United States. The continuous evolution of CPV requires that monoclonal antibody-based and nucleic acid-based diagnostic assays should be periodically checked for sensitivity on prevalent CPV strains.

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Two Distinct Genotypes of Spissistilus festinus (Say, 1830) (Hemiptera, Membracidae) in the United States Revealed by Phylogenetic and Morphological Analyses

Insects ◽

10.3390/insects11020080 ◽

2020 ◽

Vol 11 (2) ◽

pp. 80

Author(s):

Elizabeth Cieniewicz ◽

Victoria Poplaski ◽

Melina Brunelli ◽

Jason Dombroskie ◽

Marc Fuchs

Keyword(s):

United States ◽

Polymerase Chain Reaction ◽

Southeastern United States ◽

Variable Region ◽

The United States ◽

Coi Gene ◽

Its2 Region ◽

Chain Reaction ◽

Polymerase Chain ◽

Spissistilus Festinus

Spissistilus festinus (Say, 1830) (Hemiptera: Membracidae) is a frequent pest of leguminous crops in the Southern United States, and a vector of grapevine red blotch virus. There is currently no information on the genetic diversity of S. festinus. In this study, populations of S. festinus were collected in 2015–2017 from various crops and geographic locations in the United States, and fragments of the mitochondrial cytochrome C oxidase 1 (mt-COI) gene and the nuclear internal transcribed spacer 2 (ITS2) region were characterized by polymerase chain reaction and sequencing. Maximum-likelihood and Bayesian analyses of the mt-COI and ITS2 sequences yielded similar phylogenetic tree topologies, revealing two distinct genetic S. festinus lineages with all of the specimens from California comprising one phylogenetic clade, alongside a single GenBank entry from Arizona, and all specimens from the Southeastern United States comprising a statistically-supported distinct clade, regardless of host and year of collection. The mt-COI gene fragment showed up to 10.8% genetic distance between the two phylogenetic clades. These results suggest the existence of two genotypes within S. festinus in the United States. The only distinct morphological trait between the two genotypes was a less elevated pronotum in the representative specimens from California, compared to the representative specimens from the Southeastern United States. Since this phenotypic feature is inconspicuous, a diagnostic polymerase chain reaction targeting a variable region of the mt-COI fragment was developed to reliably distinguish between the specimens of the two genotypes of S. festinus and to facilitate their specific identification.

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Discovery of Heterodera filipjevi in Washington and Comparative Virulence with H. avenae on Wheat

Plant Disease ◽

10.1094/pdis-08-14-0789-re ◽

2015 ◽

Vol 99 (3) ◽

pp. 376-386 ◽

Cited By ~ 9

Author(s):

Richard W. Smiley ◽

Guiping Yan

Keyword(s):

United States ◽

The United States ◽

Cyst Nematode ◽

Cereal Cyst Nematode ◽

Heterodera Avenae ◽

Management Guidelines ◽

Polymerase Chain ◽

Species Specific ◽

Eastern Washington ◽

Cyst Morphology

The cereal cyst nematode Heterodera avenae suppresses wheat production in the western United States. A second species of cereal cyst nematode, H. filipjevi, was identified in eastern Oregon during 2008. This paper reports the discovery of H. filipjevi–infested fields in eastern Washington, thereby extending the known distribution of H. filipjevi in the United States. The identity of H. filipjevi was determined and confirmed by species-specific polymerase chain reaction (PCR), PCR-restriction fragment length polymorphism (RFLP), sequencing, and cyst morphology. Soils that were collected from naturally infested fields in Washington were used to compare the virulence of H. avenae and H. filipjevi on six spring wheat cultivars under controlled-environment conditions. Noninfested soils from nearby fields were used as controls. Cultivars Ouyen and WB Rockland were resistant to H. avenae and susceptible to H. filipjevi. Cultivars Sönmez and SY Steelhead were resistant to H. filipjevi and susceptible to H. avenae. Cultivars Louise and WB 936 were susceptible to both species. The resistance of SY Steelhead to ‘H. avenae’, reported in a previous paper, is corrected as resistance to H. filipjevi due to an earlier misidentification of H. filipjevi. Management guidelines that include crop rotations and resistant cultivars are presented. Discovery of additional infestations of H. filipjevi are anticipated when DNA-based tests become used routinely in commercial diagnostic laboratories.

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Polymerase Chain Reaction Assay for the Detection and Identification ofMycobacterium lepraein Patients in the United States

American Journal of Clinical Pathology ◽

10.1093/ajcp/109.5.642 ◽

1998 ◽

Vol 109 (5) ◽

pp. 642-646 ◽

Cited By ~ 32

Author(s):

David M. Scollard ◽

Thomas P. Gillis ◽

Diana L. Williams

Keyword(s):

United States ◽

Polymerase Chain Reaction ◽

Polymerase Chain Reaction Assay ◽

The United States ◽

Chain Reaction ◽

Detection And Identification ◽

Polymerase Chain

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Molecular Analyses of Colletotrichum Species from Almond and Other Fruits

Phytopathology ◽

10.1094/phyto.2000.90.6.608 ◽

2000 ◽

Vol 90 (6) ◽

pp. 608-614 ◽

Cited By ~ 78

Author(s):

Stanley Freeman ◽

Dror Minz ◽

Edouard Jurkevitch ◽

Marcel Maymon ◽

Ezra Shabi

Keyword(s):

United States ◽

Sequence Analysis ◽

Its Region ◽

The United States ◽

Morphological Identification ◽

Molecular Analyses ◽

Colletotrichum Species ◽

Morphological Criteria ◽

Colletotrichum Spp ◽

Polymerase Chain

Isolates of Colletotrichum spp. from almond, avocado, and strawberry from Israel and isolates of the pink subpopulation from almond from the United States were characterized by various molecular methods and compared with morphological identification. Taxon-specific primer analysis grouped the avocado isolates within the species C. gloeosporioides and the U.S. almond and Israeli strawberry isolates within the species C. acutatum. However, the Israeli almond isolates, previously identified morphologically as C. gloeosporioides, reacted with C. acutatum-specific primers. Arbitrarily primed polymerase chain reaction and A+T-rich DNA analyses determined that each population from almond and strawberry was distinct and clonal. Sequence analysis of the complete internal transcribed spacer (ITS) region (ITS 1–5.8S–ITS 2) revealed a similarity of between 97.03 and 98.72% among almond isolates from Israel, C. acutatum almond isolates from the United States, and C. acutatum strawberry isolates from Israel. Similarity of the above populations to that of C. gloeosporioides of avocado was between 92.42 and 92.86%. DNA sequence analysis of the entire ITS region supported the phylogeny inferred from the ITS 1 tree of 14 different Colletotrichum species. Although morphological criteria indicated that the Israeli isolates from almond are unique, this population was grouped within the C. acutatum species according to molecular analyses.

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