Mitochondrial dysfunction and defects in lipid homeostasis as therapeutic targets in neurodegeneration with brain iron accumulation

The syndromes of neurodegeneration with brain iron accumulation (NBIA) encompass a group of invalidating and progressive rare diseases that share the abnormal accumulation of iron in the basal ganglia. The onset of NBIA disorders ranges from infancy to adulthood. Main clinical signs are related to extrapyramidal features (dystonia, parkinsonism and choreoathetosis), and neuropsychiatric abnormalities. Ten NBIA forms are widely accepted to be caused by mutations in the genes PANK2, PLA2G6, WDR45, C19ORF12, FA2H, ATP13A2, COASY, FTL1, CP, and DCAF17. Nonetheless, many patients remain without a conclusive genetic diagnosis, which shows that there must be additional as yet undiscovered NBIA genes. In line with this, isolated cases of known monogenic disorders, and also, new genetic diseases, which present with abnormal brain iron phenotypes compatible with NBIA, have been described. Several pathways are involved in NBIA syndromes: iron and lipid metabolism, mitochondrial dynamics, and autophagy. However, many neurodegenerative conditions share features such as mitochondrial dysfunction and oxidative stress, given the bioenergetics requirements of neurons. This review aims to describe the existing link between the classical ten NBIA forms by examining their connection with mitochondrial impairment as well as oxidative stress and neuroinflammation.

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Neurodegeneration with brain iron accumulation type 4 by mutation in the C19orf12 gene: first time found in adolescent of Russian origin

Neuropediatrics ◽

10.1055/s-0033-1337851 ◽

2013 ◽

Vol 44 (02) ◽

Author(s):

E Giagkou ◽

S Lutz ◽

U Schara ◽

K Becker ◽

C Möller-Hartmann

Keyword(s):

Iron Accumulation ◽

Brain Iron ◽

First Time

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Psychotic Disorder in Neurodegeneration with Brain Iron Accumulation

Clinical Schizophrenia & Related Psychoses ◽

10.3371/1935-1232.10.3.178 ◽

2016 ◽

Vol 10 (3) ◽

pp. 178-180

Author(s):

Menekse Sila Yazar ◽

Nurhan Fistikci ◽

Ozlem Devrim Balaban ◽

Nezih Eradamlar ◽

Latif Alpkan

Keyword(s):

Psychotic Disorder ◽

Iron Accumulation ◽

Brain Iron

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Faculty Opinions recommendation of T2* and FSE MRI distinguishes four subtypes of neurodegeneration with brain iron accumulation.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1120518.576728 ◽

2008 ◽

Author(s):

Cynthia Comella

Keyword(s):

Iron Accumulation ◽

Brain Iron

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Novel deep intronic mutation in PLA2G6 causing early-onset Parkinson’s disease with brain iron accumulation through pseudo-exon activation

Neurogenetics ◽

10.1007/s10048-021-00667-0 ◽

2021 ◽

Author(s):

Chiara Cavestro ◽

Celeste Panteghini ◽

Chiara Reale ◽

Alessia Nasca ◽

Silvia Fenu ◽

...

Keyword(s):

Early Onset ◽

Cerebellar Atrophy ◽

Iron Accumulation ◽

Brain Iron ◽

Causative Gene ◽

Coding Regions ◽

Aberrant Transcript ◽

Pathogenic Variants ◽

Intronic Mutation ◽

Mrna Analysis

AbstractPLA2G6 is the causative gene for a group of autosomal recessive neurodegenerative disorders known as PLA2G6-associated neurodegeneration (PLAN). We present a case with early-onset parkinsonism, ataxia, cognitive decline, cerebellar atrophy, and brain iron accumulation. Sequencing of PLA2G6 coding regions identified only a heterozygous nonsense variant, but mRNA analysis revealed the presence of an aberrant transcript isoform due to a novel deep intronic variant (c.2035-274G > A) leading to activation of an intronic pseudo-exon. These results expand the genotypic spectrum of PLAN, showing the paramount importance of detecting possible pathogenic variants in deep intronic regions in undiagnosed patients.

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Rare Gain-of-Function KCND3 Variant Associated with Cerebellar Ataxia, Parkinsonism, Cognitive Dysfunction, and Brain Iron Accumulation

International Journal of Molecular Sciences ◽

10.3390/ijms22158247 ◽

2021 ◽

Vol 22 (15) ◽

pp. 8247

Author(s):

Cheng-Tsung Hsiao ◽

Thomas F. Tropea ◽

Ssu-Ju Fu ◽

Tanya M. Bardakjian ◽

Pedro Gonzalez-Alegre ◽

...

Keyword(s):

Cerebellar Ataxia ◽

Iron Accumulation ◽

Molecular Spectra ◽

Loss Of Function ◽

Brain Iron ◽

Gain Of Function ◽

Progressive Cerebellar Ataxia ◽

Voltage Dependent ◽

Window Current

Loss-of-function mutations in the KV4.3 channel-encoding KCND3 gene are linked to neurodegenerative cerebellar ataxia. Patients suffering from neurodegeneration associated with iron deposition may also present with cerebellar ataxia. The mechanism underlying brain iron accumulation remains unclear. Here, we aim to ascertain the potential pathogenic role of KCND3 variant in iron accumulation-related cerebellar ataxia. We presented a patient with slowly progressive cerebellar ataxia, parkinsonism, cognitive impairment, and iron accumulation in the basal ganglia and the cerebellum. Whole exome sequencing analyses identified in the patient a heterozygous KCND3 c.1256G>A (p.R419H) variant predicted to be disease-causing by multiple bioinformatic analyses. In vitro biochemical and immunofluorescence examinations revealed that, compared to the human KV4.3 wild-type channel, the p.R419H variant exhibited normal protein abundance and subcellular localization pattern. Electrophysiological investigation, however, demonstrated that the KV4.3 p.R419H variant was associated with a dominant increase in potassium current amplitudes, as well as notable changes in voltage-dependent gating properties leading to enhanced potassium window current. These observations indicate that, in direct contrast with the loss-of-function KCND3 mutations previously reported in cerebellar ataxia patients, we identified a rare gain-of-function KCND3 variant that may expand the clinical and molecular spectra of neurodegenerative cerebellar disorders associated with brain iron accumulation.

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Clinical and genetic delineation of neurodegeneration with brain iron accumulation

Journal of Medical Genetics ◽

10.1136/jmg.2008.061929 ◽

2008 ◽

Vol 46 (2) ◽

pp. 73-80 ◽

Cited By ~ 213

Author(s):

A Gregory ◽

B J Polster ◽

S J Hayflick

Keyword(s):

Iron Accumulation ◽

Brain Iron

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WDR45 Gene and Its Role in Pediatric Epilepsies

Journal of Pediatric Neurology ◽

10.1055/s-0041-1727174 ◽

2021 ◽

Author(s):

Federica Filosco ◽

Sebastiano Billone ◽

Ausilia Collotta ◽

Tiziana Timpanaro ◽

Monica Tosto ◽

...

Keyword(s):

Language Impairment ◽

Pediatric Patients ◽

De Novo ◽

Somatic Mosaicism ◽

Brain Magnetic Resonance Imaging ◽

Iron Accumulation ◽

Psychomotor Development ◽

Specific Gene ◽

Brain Iron ◽

De Novo Mutations

AbstractWD repeat domain 45 (WDR45) gene has been increasingly found in patients with developmental delay (DD) and epilepsy. Previously, WDR45 de novo mutations were reported in sporadic adult and pediatric patients presenting iron accumulation, while heterozygous mutations were associated with β-propeller protein-associated neurodegeneration (BPAN), a subtype of neurodegeneration with brain iron accumulation disorders, characterized by extrapyramidal movement disorders and abnormal accumulation of iron in the basal ganglia. Overall, people harboring WDR45 mutations have moderate to severe DD and different types of seizures. The phenotype of adult patients is characterized by extrapyramidal movement, dystonia, parkinsonism, language impairment, and involvement of the substantia nigra and in the globus pallidus at brain magnetic resonance imaging. Importantly, there are no findings of brain iron accumulation in brain in BPAN patients in the first decade of life, thus suggesting a progressive course of the disease. Comparatively, the main phenotype of pediatric patients is epilepsy with early onset, most of which present infantile spasms and arrest or regression of psychomotor development. The phenotype of patients with WDR45 mutations is variable, being different if caused by somatic mosaicism or germline mutations, and presenting with a different spectrum of manifestations in males and females. The treatment of affected individuals is symptomatic. Regarding the seizures, specific, gene-based approaches with specific antiepileptic drugs are not currently available. The early diagnosis of BPAN could be useful in some aspects, such as providing families a supportive treatment to their affected children.

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