Dataset Information

Genetics of Hereditary Ataxia in Scottish Terriers.

ABSTRACT:

Background

Scottish Terriers have a high incidence of juvenile onset hereditary ataxia primarily affecting the Purkinje neuron of the cerebellar cortex and causing slowly progressive cerebellar dysfunction.

Objective

To identify chromosomal regions associated with hereditary ataxia in Scottish Terriers.

Animals

One hundred and fifty-three Scottish Terriers were recruited through the Scottish Terrier Club of America.

Materials and methods

Prospective study. Dogs were classified as affected if they had slowly progressive cerebellar signs. When possible, magnetic resonance imaging and histopathological evaluation of the brain were completed as diagnostic aids. To identify genomic regions connected with the disease, genome-wide mapping was performed using both linkage- and association-based approaches. Pedigree evaluation and homozygosity mapping were also performed to examine mode of inheritance and to investigate the region of interest, respectively.

Results

Linkage and genome-wide association studies in a cohort of Scottish Terriers both identified a region on CFA X strongly associated with the disease trait. Homozygosity mapping revealed a 4 Mb region of interest. Pedigree evaluation failed to identify the possible mode of inheritance due to the lack of complete litter information.

Conclusion and clinical importance

This finding suggests that further genetic investigation of the potential region of interest on CFA X should be considered in order to identify the causal mutation as well as develop a genetic test to eliminate the disease from this breed.

SUBMITTER: Urkasemsin G

PROVIDER: S-EPMC5508367 | biostudies-literature | 2017 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Genetics of Hereditary Ataxia in Scottish Terriers.

Urkasemsin G G Nielsen D M DM Singleton A A Arepalli S S Hernandez D D Agler C C Olby N J NJ

Journal of veterinary internal medicine 20170529 4

<h4>Background</h4>Scottish Terriers have a high incidence of juvenile onset hereditary ataxia primarily affecting the Purkinje neuron of the cerebellar cortex and causing slowly progressive cerebellar dysfunction.<h4>Objective</h4>To identify chromosomal regions associated with hereditary ataxia in Scottish Terriers.<h4>Animals</h4>One hundred and fifty-three Scottish Terriers were recruited through the Scottish Terrier Club of America.<h4>Materials and methods</h4>Prospective study. Dogs were ...[more]

PMID: 28556454

Similar Datasets

Project description:BackgroundThe genetics of cerebellar ataxia is complex. Hundreds of causative genes have been identified, but only a few cause more than single cases. The spectrum of ataxia-causing genes differs considerably between populations. The aim of the study was to investigate the molecular epidemiology of ataxia in the Finnish population.Patients and methodsAll patients in hospital database were reviewed for the diagnosis of unspecified ataxia. Acquired ataxias and nongenetic ataxias such as those related to infection, trauma or stroke were excluded. Sixty patients with sporadic ataxia with unknown etiology and 36 patients with familial ataxia of unknown etiology were recruited in the study. Repeat expansions in the SCA genes (ATXN1, 2, 3, 7, 8/OS, CACNA1A, TBP), FXN, and RFC1 were determined. Point mutations in POLG, SPG7 and in mitochondrial DNA (mtDNA) were investigated. In addition, DNA from 8 patients was exome sequenced.ResultsA genetic cause of ataxia was found in 33 patients (34.4%). Seven patients had a dominantly inherited repeat expansion in ATXN8/OS. Ten patients had mitochondrial ataxia resulting from mutations in nuclear mitochondrial genes POLG or RARS2, or from a point mutation m.8561C > G or a single deletion in mtDNA. Interestingly, five patients were biallelic for the recently identified pathogenic repeat expansion in RFC1. All the five patients presented with the phenotype of cerebellar ataxia, neuropathy, and vestibular areflexia (CANVAS). Moreover, screening of 54 patients with Charcot-Marie-Tooth neuropathy revealed four additional patients with biallelic repeat expansion in RFC1, but none of them had cerebellar symptoms.ConclusionsExpansion in ATXN8/OS results in the majority of dominant ataxias in Finland, while mutations in RFC1 and POLG are the most common cause of recessive ataxias. Our results suggest that analysis of RFC1 should be included in the routine diagnostics of idiopathic ataxia and Charcot-Marie-Tooth polyneuropathy.

Project description:Clinicoanatomic correlation in the spinocerebellar ataxias (SCA) and Friedreich's ataxia (FRDA) is difficult as these diseases differentially affect multiple sites in the central and peripheral nervous systems. A new way to study cerebellar ataxia is the systematic analysis of the "reciprocal cerebellar circuitry" that consists of tightly organized reciprocal connections between Purkinje cells, dentate nuclei (DN), and inferior olivary nuclei (ION). This circuitry is similar to but not identical with the "cerebellar module" in experimental animals. Neurohumoral transmitters operating in the circuitry are both inhibitory (γ-aminobutyric acid in corticonuclear and dentato-olivary fibers) and excitatory (glutamate in olivocerebellar or climbing fibers). Glutamatergic climbing fibers also issue collaterals to the DN. The present study applied five immunohistochemical markers in six types of SCA (1, 2, 3, 6, 7, 17), genetically undefined SCA, FRDA, and FRDA carriers to identify interruptions within the circuitry: calbindin-D28k, neuron-specific enolase, glutamic acid decarboxylase, and vesicular glutamate transporters 1 and 2. Lesions of the cerebellar cortex, DN, and ION were scored according to a guide as 0 (normal), 1 (mild), 2 (moderate), and 3 (severe). Results of each of the five immunohistochemical stains were examined separately for each of the three regions. Combining scores of each anatomical region and each stain yielded a total score as an indicator of pathological severity. Total scores ranged from 16 to 38 in SCA-1 (nine cases); 22 to 39 in SCA-2 (six cases); 9 to 15 in SCA-3 (four cases); and 13 and 25 in SCA-6 (two cases). In single cases of SCA-7 and SCA-17, scores were 16 and 31, respectively. In two genetically undefined SCA, scores were 36 and 37, respectively. In nine cases of FRDA, total scores ranged from 11 to 19. The low scores in SCA-3 and FRDA reflect selective atrophy of the DN. The FRDA carriers did not differ from normal controls. These observations offer a semiquantitative assessment of the critical role of the DN in the ataxic phenotype of SCA and FRDA while other parts of the circuitry appear less important.

Dataset Information

Genetics of Hereditary Ataxia in Scottish Terriers.

Background

Objective

Animals

Materials and methods

Results

Conclusion and clinical importance

Publications

Genetics of Hereditary Ataxia in Scottish Terriers.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets