Proteomic analysis of serum from a MeCP2 patient reveals an arginine biosynthesis pathway affected by the p.Lys254* variant

Key Clinical Message This study reports a Chinese male patient with a novel MeCP2 p.Lys254*variant. Upon birth, the patient presented with typical symptoms, such as abnormal electroencephalogram, immature sleep rhythm, hypotonia, feeding difficulties, pulmonary fluid accumulation, horizontal fissures in the lungs, hypoventilation, and heart defects. Abstract MeCP2 is a gene located on the X chromosome and the main pathogenic gene responsible for Rett syndrome, which mainly occurs in females. Herein, we identified a male patient with a novel MeCP2 p.Lys254* variant through whole‐exome sequencing, although both parents are wild type. Upon birth, the patient presented with typical symptoms, such as abnormal electroencephalogram, immature sleep rhythm, hypotonia, feeding difficulties, pulmonary fluid accumulation, horizontal fissures in the lungs, hypoventilation, and other symptoms. Period of breathing support, but also found that the boy had a heart defect and horizontal fissure in the lungs. Our discovery of a new spontaneous MeCP2 nonsense mutation enriches the understanding of Rett syndrome and provides a reference for its early diagnosis and treatment.