Cerebral folate deficiency syndromes in childhood: clinical, analytical, and etiologic aspects.

BACKGROUND: Cerebral folate deficiency may be amenable to therapeutic supplementation. Diverse metabolic pathways and unrelated processes can lead to cerebrospinal fluid 5-methyltetrahydrofolate (5-MTHF) depletion, the hallmark of cerebral folate deficiency. OBJECTIVE: To analyze cerebral folate abundance in a large prospective series of children diagnosed with any neurologic disorder for which a diagnostic lumbar puncture was indicated. DESIGN: We studied the spectrum and frequency of disorders associated with cerebral folate deficiency by measuring cerebrospinal fluid 5-MTHF, biogenic amines, and pterins. Direct sequencing of the FOLR1 transporter gene was also performed in some patients. SETTING: Academic pediatric medical center. PARTICIPANTS: We studied 134 individuals free of neurometabolic disease and 584 patients with any of several diseases of the central nervous system. RESULTS: Of 584 patients, 71 (12%) exhibited 5-MTHF deficiency. Mild to moderate deficiency (n = 63; range, 19-63 nmol/L) was associated with perinatal asphyxia, central nervous system infection, or diseases of probable genetic origin (inborn errors of metabolism, white matter disorders, Rett syndrome, or epileptic encephalopathies). Severe 5-MTHF depletion (n = 8; range, 0.6-13 nmol/L) was detected in severe MTHF reductase deficiency, Kearns-Sayre syndrome, biotin-responsive striatal necrosis, acute necrotizing encephalitis of Hurst, and FOLR1 defect. A strong correlation was observed between cerebrospinal fluid and plasma folate levels in cerebral folate deficiency. CONCLUSIONS: Of the 2 main forms of cerebral folate deficiency identified, mild to moderate 5-MTHF deficiency was most commonly associated with disorders bearing no primary relation to folate metabolism, whereas profound 5-MTHF depletion was associated with specific mitochondrial disorders, metabolic and transporter defects, or cerebral degenerations. The results suggest that 5-MTHF can serve either as the hallmark of inborn disorders of folate transport and metabolism or, more frequently, as an indicator of neurologic dysfunction.

Agenesis of internal carotid artery in a child with ipsilateral Horner's syndrome.

Horner's syndrome is characterized by a classic triad of ipsilateral pupillary miosis, partial eyelid ptosis, and facial anhydrosis. This case study reports a 7-year-old boy with right miosis, mild blepharoptosis, and iris hypopigmentation detected in a routine pediatric follow-up without ipsilateral facial anhydrosis, flushing, or pain. There was no history of birth trauma and test with cocaine provoked no response of the right pupil, suggesting right Horner's syndrome. Mediastinal tumor was ruled out and brain magnetic resonance imaging incidentally showed absence of flow in the right internal carotid artery. Subsequent magnetic resonance angiography demonstrated agenesis of the right internal carotid artery without other vascular-associated malformations. The final diagnosis was right, congenital Horner's syndrome due to ipsilateral internal carotid agenesis. We describe in detail the radiological findings and pathophysiological mechanisms of this unusual association.