RESUMO
OBJECTIVE: To explore the clinical characteristics and genetic etiology of three children with Menkes disease. METHODS: Three children who had presented at the Children's Medical Center, the Affiliated Hospital of Guangdong Medical University from January 2020 to July 2022 were selected as the study subjects. Clinical data of the children were reviewed. Genomic DNA was extracted from peripheral blood samples of the children, their parents and sister of child 1. Whole exome sequencing (WES) was carried out. Candidate variants were verified by Sanger sequencing, copy number variation sequencing (CNV-seq), and bioinformatic analysis. RESULTS: Child 1 was a 1-year-and-4-month male, and children 2 and 3 were monozygotic twin males aged 1-year-and-10-month. The clinical manifestations of the three children have included developmental delay and seizures. WES showed that child 1 has harbored a c.3294+1G>A variant of the ATP7A gene. Sanger sequencing confirmed that his parents and sister did not carry the same variant, suggesting that it was de novo. Children 2 and 3 had carried a c.77266650_77267178del copy number variation. CNV-seq results showed that their mother has carried the same variant. By searching the HGMD, OMIM and ClinVar databases, the c.3294+1G>A was known to be pathogenic. No carrier frequency has been recorded in the 1000 Genomes, ESP, ExAC and gnomAD databases. Based on the Standards and Guidelines for the Interpretation of Sequence Variants: A Joint Consensus Recommendation of the American College of Medical Genetics and Genomics (ACMG), the ATP7A gene c.3294+1G>A variant was predicted to be pathogenic. The c.77266650_77267178del variant has involved exons 8 to 9 of the ATP7A gene. ClinGen online system score for it was 1.8, which was also considered to be pathogenic. CONCLUSION: The c.3294+1G>A and c.77266650_ 77267178del variants of the ATP7A gene probably underlay the Menkes disease in the three children. Above finding has enriched the mutational spectrum of Menkes disease and provided a basis for clinical diagnosis and genetic counseling.
