Objective: To describe the phenomenology of SCAR9, caused by a homozygotic mutation in COQ8A gene, and to describe the positive effects of a holistic approach to the treatment.

Background: Coenzyme Q10 deficiency causes a variety of rare genetic conditions. Autosomal recessive spinocerebellar ataxia 9 (SCAR9) is caused by mutations of COQ8A gene, characterized by dystonia, epilepsy, tremor and ataxia.

Method: Description of two siblings carrying the same homozygotic mutation and presenting with different phenomenology.

Results: A 21-year-old boy presented with a complex neurologic syndrome, started 6 years previously with exercise intolerance, rigidity of the right lower limb, myoclonus of the upper limbs, head and right lower limb, dystonia of the feet, dystonic posture of the hands and episodes characterized by stereotyped behaviours and visual hallucinations, as well as episodes characterized by jerks of the right side of his face, which lasted some seconds. We performed: abdomen ultrasound (hepatomegaly), EMG, EEG, ophthalmologic assessment, urine copper, lumbar puncture, autoimmune assessment, levodopa challenge, brain MRI, neuropsychological tests (all normal) and genetic testing, which enabled us to make the diagnosis. Our approach to treatment is a holistic one, since it involves rehabilitation, both physical and cognitive, logopaedic sessions, pharmacologic treatment and botulinum toxin injections. We have been following him up for four years. His cognition is now affected as well (prominent visuo-spatial deficits and executive dysfunction). He undergoes cycles of worsening and improving, and he still has an optimal response to treatment. His younger brother never complained of any neurological symptom. Nevertheless, on neurological examination he showed: polykinetic reflexes, Babinski sign, postural and kinetic tremor, dystonic posture of the hands, frenage on finger-nose test. We performed neuropsychological evaluation (normal), brain MRI (cerebellar atrophy) and genetic testing (positive). We treat him with ubidecarenone and physical activity, and we have not seen any neurological worsening in our six-months follow-up.

Conclusion: SCAR9 is a rare neurological disorder, presenting with a heterogeneous phenomenology. Making an early diagnosis is of paramount importance in order to ensure early treatment with a holistic approach to patients.

References: 1. Alcazar-Fabra Maria, Brea-Calvo Gloria, Clinical syndromes associated with Coenzyme Q10 deficiency, Essays in Biochemistry (2018) 62 377–398, doi 10.1042/EBC20170107
2. Alcazar-Fabra Maria, Rodriguez-Sanchez Francisco, Trevisson Eva, Brea-Calvo Gloria, Primary Coenzyme Q10 deficiencies; a literature review and online platform of clinical features to uncover genotype-phenotype correlations, Free Radical Biology and Medicine 167 (2021) 141–180, doi 0.1016/j.freeradbiomed.2021.02.046
3. Balreira Andrea, Boczonadin Veronika, Barca Emanuele, Pyle Angela, Bansagi Boglarka, Appleton Marie, Graham Claire, Hargreaves Iain P, Milic Rasic Vedrana, Lochmuller Hanns, Griffin Helen, Taylor Robert W, Naini A, Chinnery Patrick F, Hirano Michio, Quinzii Catarina M, Horvath Rita, ANO10 mutations cause ataxia and Coenzyme Q10 deficiency, J Neurol (2014) 261:2192–2198 DOI 10.1007/s00415-014-7476-7
4. Chang Anna, Ruiz-Lopez Marta, Slow Elizabeth, Tarnopolsky Mark, Lang Anthony E, Munhoz Renato P, ADCK3-related Coenzyme Q10 deficiency: a potentially treatable genetic disease, Mov Dis Clin Pract 2018; 5(6): 635–639. doi: 10.1002/mdc3.12667
5. Galosi Serena, Barca Emanuele, Carrozzo Rosalba, Schirinzi Tommaso, Quinzii Catarina Maria, Lieto Maria, Vasco Gessica, Zanni Ginevra, Di Nottia Michela, Galatolo Daniele, Filla Alessandro, Bertini Enrico, Santorelli Filippo Maria, Leuzzi Vincenzo, Haas Richard, Hirano Michio, Friedman Jennifer, Dystonia-Ataxia with early handwriting deterioration in COQ8A mutation carriers: a case series and literature review, Park Rel Dis 68 (2019) 8-16, doi /10.1016/j.parkreldis.2019.09.015

« Back to 2024 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/phenomenology-of-coenzyme-q10-deficiency-spinocerebellar-ataxia-case-description-of-two-siblings-and-new-therapeutic-perspectives/