Epileptic Disorders


Photoparoxysmal response in ADCK3 autosomal recessive ataxia: a case report and literature review Volume 23, numéro 1, February 2021


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1 Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, University of Genoa, Genoa, Italy
2 Unit of Child Neuropsychiatry, Epilepsy Centre, Department of Medical and Surgical Neuroscience and Rehabilitation, IRCCS Istituto Giannina Gaslini, Genoa, Italy
3 Unit of Child Neuropsychiatry, Department of Neurosciences, ASST Fatebenefratelli-Sacco, Milan, Italy
4 Neuroradiology Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy
5 Unit of Neuromuscular and Neurodegenerative Disorders, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy
* Correspondence: Sara Uccella Unit of Child Neuropsychiatry, Epilepsy Centre IRCCS Istituto Giannina Gaslini, Largo Gaslini 5, 16147 Genova, Italy

Mutations in AarF domain-containing kinase 3 (ADCK3) are responsible for the most frequent form of hereditary coenzyme Q10 (CoQ10) deficiency (Q10 deficiency-4), which is mainly associated with autosomal recessive cerebellar ataxia type 2 (ARCA2). Clinical presentation is characterized by a variable degree of cerebellar atrophy and a broad spectrum of associated symptoms, including muscular involvement, movement disorders, neurosensory loss, cognitive impairment, psychiatric symptoms and epilepsy. In this report, we describe, for the first time, a case of photoparoxysmal response in a female patient with a mutation in ADCK3. Disease onset occurred in early childhood with gait ataxia, and mild-to-moderate degeneration. Seizures appeared at eight years and six months, occurring only during sleep. Photoparoxysmal response was observed at 14 years, almost concomitant with the genetic diagnosis (c.901C>T;c.589-3C>G) and the start of CoQ10 oral supplementation. A year later, disease progression slowed down, and photosensitivity was attenuated. A review of the literature is provided focusing on epileptic features of ADCK3-related disease as well as the physiopathology of photoparoxysmal response and supposed cerebellar involvement in photosensitivity. Moreover, the potential role of CoQ10 oral supplementation is discussed. Prospective studies on larger populations are needed to further understand these data.