The phenotype caused by recessive variations in SLC25A22: Report of a new case and literature review

M.-V. André (1) , Pierre Cacciagli (2) , A. Cano , L. Vaugier , M. Roussel , N. Girard , Brigitte Chabrol , Laurent Villard (2, 3) , Mathieu Milh (1)

1 Service de pédiatrie et neurologie pédiatrique
2 MMG - Marseille medical genetics - Centre de génétique médicale de Marseille
3 Département de génétique médicale [Hôpital de la Timone - APHM]

We describe the clinical, electroencephalography (EEG), and developmental features of a patient with developmental and epileptic encephalopathy due to a homozygous pathogenic variation of mitochondrial glutamate/H+ symporter SLC25A22. Epilepsy began during the first week of life with focal onset seizures. Interictal EEG revealed a suppression-burst pattern with extensive periods of non-activity. The prospective follow-up confirmed developmental encephalopathy as well as ongoing active epilepsy and almost no sign of development at 8 years of age. We confirm in the following paper that SLC25A22 recessive variations may cause a severe developmental and epileptic encephalopathy characterized by a suppression-burst pattern. On the basis of an in-depth literature review, we also provide an overview of this rare genetic cause of neonatal onset epilepsy.

Keywords: Early developmental and epileptic encephalopathy; Myoclonic seizures; SLC25A22; Suppression-burst.

Domains: Life Sciences [q-bio]; Life Sciences [q-bio]; Genetics; Life Sciences [q-bio]; Genetics; Human genetics

M.-V. André, Pierre Cacciagli, A. Cano, L. Vaugier, M. Roussel, et al.. The phenotype caused by recessive variations in SLC25A22: Report of a new case and literature review. Archives de Pédiatrie, 2021, 28 (1), pp.87-92. ⟨10.1016/j.arcped.2020.10.015⟩. ⟨hal-03148905⟩