Background: Frontoethmoidal encephalocele (FEE) is a neural tube defect (NTD) characterized by a congenital bone defect in the anterior cranium and herniation of the intracranial mass through the defect. The C677T mutation in the 5,10-methylenetetrahydrofolate reductase gene (MTHFR) has been reported as a genetic risk factor for spina bifida. However, the role of the MTHFR in the pathogenesis of FEE remains to be clarified.
Methods: A hospital-based survey of FEE patients who were referred to the Department of Neurosurgery and Plastic Surgery, Malang General Hospital, East Java, Indonesia was conducted. Genetic screening of MTHFR substitutions in 13 patients and eight mothers from 11 affected families were performed using a combination of polymerase chain reaction (PCR), denaturing high-performance liquid chromatography (DHPLC), and direct sequencing.
Results: In total, 130 patients with FEE among 138 NTD patients (94.2%) were identified. The ratios of cranial encephalomeningocele to spinal meningocele (32 : 1) and of FEE to occipital encephalomeningocele (32 : 1) were higher than those in other populations. Five substitutions were detected in the MTHFR: C121T, C677T, C1060T, A1298C, and G1793A. No significant differences were found in the frequency of each nucleotide substitution between patients or mothers and controls. In addition, none of the subjects in this study were homozygous for T at nucleotide position 677.
Conclusion: FEE is the most common form of NTD in East Java, Indonesia. Genetic analysis of 11 affected families suggests that the MTHFR gene is not associated with the development of FEE, although the number of FEE families analyzed in this study was very limited.