Abstract:  Objective To summarize the clinical features of children with congenital Rett variant caused by mutation of FOXG1 and provide the reference for the diagnosis and treatment of the disease. Methods The clinical data of a patient diagnosed as congenital Rett syndrome variant type were summarized. The DNA samples of peripheral blood from the patient and her parents were extracted. The targeted high-throughput sequencing technology was used to detect the sequence of targeted genes, which were associated with the symptoms of the child. Genes were then verified by sanger sequencing. Chromosomal microarray analysis was performed to detect chromosome microdeletions and microduplications. Results The child carried the c. 506dupG, p.G169Gfs ＊ 286 heterozygous mutations on FOXG1 gene, which located in 14q12, and her parents were wild-type. After querying the HGMD, Clinvar and dbSNP databases, we found that it was not reported. This case was clearly diagnosed as congenital Rett syndrome variant type. We confirmed that the mutation locus was a new mutation. Conclusion For cases with congenital Rett variant manifestations, FOXG1 gene mutation examination is recommended, and preventive treatment of partially predictable dysfunction should be carried out.

Key words: point mutation, Rett syndrome, FOXG1, congenital variant, clinical features