"Progressive myoclonic ataxia and developmental/epileptic encephalopathy associated with a novel homozygous mutation in TCN2 gene".

BACKGROUND: Transcobalamin II (TCN2) defect is a rare metabolic disorder associated with a range of neurological manifestations, including mild developmental delay, severe intellectual disability, ataxia, and, in some cases, seizures. Cobalamin, an essential nutrient, plays a crucial role in central nervous system myelination. CLINICAL PRESENTATION: We present a family with an index patient who exhibited progressive neurodevelopmental regression starting at 9 months of age, accompanied by myoclonic seizures, ataxia, and tremor. No significant hematological abnormalities were observed. Exome sequencing analysis identified a novel homozygous mutation, c.3G>A - P(Met1I), affecting the acceptor site of intron 4 of the TCN2 gene (chromosome 22: 31003321, NM_000355.4), leading to likely pathogenic variant potentially affecting translation. Following treatment with hydroxocobalamin, the patient demonstrated partial clinical improvement. He has a sibling with overt hematological abnormalities and subtle neurological abnormalities who is homozygous to the same mutation. Both parents are heterozygous for the same mutation. CONCLUSIONS: In infants presenting with unexplained non-specific neurological symptoms, irrespective of classical signs of vitamin B12 deficiency, evaluation for TCN2 defect should be considered. Early diagnosis and appropriate management can lead to favorable outcomes.

An Unusual Case of Headache in a Child: Idiopathic Intracranial Hypertension with Diagnostic Challenge.

Introduction: In children, idiopathic intracranial hypertension (IIH) is relatively uncommon. It is characterized by an increase in intracranial pressure, in the absence of evidence of underlying brain disease, structural abnormalities, hydrocephalus, or abnormal meningeal improvement. However, very rarely it can occur without papilledema, even though it is the most recognizable clinical sign. Due to this, a delay in diagnosis can lead to severe visual impairments. Case presentation: We describe a patient with a chronic headache but no papilledema. His neurological and systemic examinations were otherwise unremarkable. A lumbar puncture revealed a high opening pressure of 450 mmH2O and normal cerebrospinal fluid (CSF) parameters. Magnetic resonance imaging of the brain revealed only tortuous optic nerves, no parenchymal lesions, and no evidence of venous sinus thrombosis. He required acetazolamide treatment. Our patient's symptoms improved significantly in 2 months with medical treatment, weight loss, and exercise, with no development of papilledema. Conclusion: There is a wide range of clinical manifestations of IIH, making it difficult to decide when to begin treatment.