Early onset developmental and epileptic encephalopathy linked to monogenic ALG13 mutation: an important differential diagnosis in refractory West syndrome – a case report

*Correspondence: [e-mail].

Abstract

Case Presentation: A 3-years-old female patient developed epileptic spasms and global hypotonia beginning at three months of age, associated with loss of development markers, like social smiling and cephalic support. She was born at term, without any relevant prenatal or obstetric comorbidities. Her familial history was unremarkable. Her electroencephalogram showed a hypsarrhythmia pattern with no abnormalities in the brain MRI and metabolic screening. She was diagnosed with West Syndrome and started Vigabatrin therapy, with no clinical response, two cycles of ACTH and oral corticotherapy with partial improvement. Due to the lack of clinical improvement, an exome was requested, which identified an ALG13 pathogenic variant. She evolved with severe global developmental delay and drug resistant epilepsy. She remains with partial seizure control with optimized anti-seizure therapy, associated with ketogenic diet.

Discussion: Epileptic encephalopathy is a condition in which the epileptic activity itself contributes to cognitive and behavioral impairment beyond that expected from the pathology alone. However, the abnormal development may not be due to seizures and interictal epileptiform abnormalities alone but arises as a direct consequence of the underlying etiology, thus also configuring a developmental encephalopathy. The differential diagnosis of developmental and epileptic encephalopathy is wide, and involves congenital disorders of glycosylation (CDG), like our case. The CDG are a group of metabolic disorders that can present with a broad and nonspecific spectrum of clinical symptoms. One such type is ALG13-CDG (Asparagine 13-linked glycosylation deficiency). Pathogenic variants in ALG13 cause a congenital disorder in which individuals exhibit variable clinical phenotypes that include developmental delay, intellectual disability and infantile spasms, characterizing a form of developmental encephalopathy and early infantile epilepsy. Another important aspect to note is that, in the face of a picture of intractable infantile spasms, the ketogenic diet, is increasingly described as beneficial, with a substantial reduction in the number and severity of crises, realized in the case described.

Final Comments: We present a rare case of a genetic developmental and epileptic encephalopathy linked to asparagine 13-linked glycosylation deficiency (ALG13). This case highlights the importance of extending the differential diagnosis in cases of refractory West Syndrome and developmental and epileptic encephalopathy.

Publication History

Article published online:
12 May 2025