| 1. |
- Brockmann, Sarah J., et al.
(författare)
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CHCHD10 mutations p.R15L and p.G66V cause motoneuron disease by haploinsufficiency
- 2018
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Ingår i: Human Molecular Genetics. - : Oxford University Press. - 0964-6906 .- 1460-2083. ; 27:4, s. 706-715
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Tidskriftsartikel (refereegranskat)abstract
- Mutations in the mitochondrially located protein CHCHD10 cause motoneuron disease by an unknown mechanism. In this study, we investigate the mutations p. R15L and p. G66V in comparison to wild-type CHCHD10 and the non-pathogenic variant p. P34S in vitro, in patient cells as well as in the vertebrate in vivo model zebrafish. We demonstrate a reduction of CHCHD10 protein levels in p. R15L and p. G66V mutant patient cells to approximately 50%. Quantitative real-time PCR revealed that expression of CHCHD10 p. R15L, but not of CHCHD10 p. G66V, is already abrogated at the mRNA level. Altered secondary structure and rapid protein degradation are observed with regard to the CHCHD10 p. G66V mutant. In contrast, no significant differences in expression, degradation rate or secondary structure of non-pathogenic CHCHD10 p. P34S are detected when compared with wild-type protein. Knockdown of CHCHD10 expression in zebrafish to about 50% causes motoneuron pathology, abnormal myofibrillar structure and motility deficits in vivo. Thus, our data show that the CHCHD10 mutations p. R15L and p. G66V cause motoneuron disease primarily based on haploinsufficiency of CHCHD10.
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| 2. |
- Cooper, Helen M., et al.
(författare)
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ATPase-deficient mitochondrial inner membrane protein ATAD3A disturbs mitochondrial dynamics in dominant hereditary spastic paraplegia
- 2017
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Ingår i: Human Molecular Genetics. - : Oxford University Press. - 0964-6906 .- 1460-2083. ; 26:8, s. 1432-1443
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Tidskriftsartikel (refereegranskat)abstract
- De novo mutations in ATAD3A (ATPase family AAA-domain containing protein 3A) were recently found to cause a neurological syndrome with developmental delay, hypotonia, spasticity, optic atrophy, axonal neuropathy, and hypertrophic cardiomyopathy. Using whole-exome sequencing, we identified a dominantly inherited heterozygous variant c.1064G > A (p.G355D) in ATAD3A in a mother presenting with hereditary spastic paraplegia (HSP) and axonal neuropathy and her son with dyskinetic cerebral palsy, both with disease onset in childhood. HSP is a clinically and genetically heterogeneous disorder of the upper motor neurons. Symptoms beginning in early childhood may resemble spastic cerebral palsy. The function of ATAD3A, a mitochondrial inner membrane AAA ATPase, is yet undefined. AAA ATPases form hexameric rings, which are catalytically dependent on the co-operation of the subunits. The dominant-negative patient mutation affects the Walker A motif, which is responsible for ATP binding in the AAA module of ATAD3A, and we show that the recombinant mutant ATAD3A protein has a markedly reduced ATPase activity. We further show that overexpression of the mutant ATAD3A fragments the mitochondrial network and induces lysosome mass. Similarly, we observed altered dynamics of the mitochondrial network and increased lysosomes in patient fibroblasts and neurons derived through differentiation of patient-specific induced pluripotent stem cells. These alterations were verified in patient fibroblasts to associate with upregulated basal autophagy through mTOR inactivation, resembling starvation. Mutations in ATAD3A can thus be dominantly inherited and underlie variable neurological phenotypes, including HSP, with intrafamiliar variability. This finding extends the group of mitochondrial inner membrane AAA proteins associated with spasticity.
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| 3. |
- Raheem, Olayinka, et al.
(författare)
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Hartia-lantiodystrofioiden molekyyligenetiikka Suomessa
- 2006
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Ingår i: Duodecim; lääketieteellinen aikakauskirja. - 0012-7183. ; 122:17, s. 2130-2136
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Tidskriftsartikel (refereegranskat)abstract
- Hartia-lantiolihasdystrofia (limb girdle muscular dystrophy, LGMD) oli ennen kyseisen taudin geenien löytämistä käytetty diagnoosi potilasryhmälle, jolla ei ole todettu muuta tunnistettua dystrofiaa, kuten X-kromosomaalista Duchennen tai Beckerin lihasdystrofiaa, vallitsevasti periytyvää fasioskapulohumeraalista lihasdystrofiaa, distaalista myopatiaa tai synnynnäistä lihasdystrofiaa. Suomessa tämän ryhmän potilailla on usein ollut diagnoosina dystrophia musculorum progressiva NUD. Vuonna 1991 löydettiin ensimmäinen LGMD:tä aiheuttava geenivirhe, ja nykyään voidaan molekyyligeneettisesti eritellä 17 eri alalajia, eivätkä nämäkään kata kaikkia tapauksia. Joidenkin alalajien diagnoosi on ollut mahdollista tehdä proteiinipuutoksen osoittavalla immunohistokemiallisella biopsialeikkeen värjäyksellä, ja menetelmä on tarjolla maamme neuropatologian laboratorioissa. TAYS:aan perustetussa lihastautien erityisdiagnostiikan keskuksessa on mahdollista etsiä tämän ryhmän geeni- ja proteiinivirheitä DNA- ja Western blotting -menetelmin. Mutaatiot kalpaiini 3-, FKRP- (fukutin-related protein) ja alfasarkoglykaanigeeneissä näyttävät olevan tärkeimmät suomalaisessa väestössä.
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