[Developmental disorder in girls due to Rett syndrome]

Area of Science:

• Neuroscience
• Genetics
• Developmental Biology

Background:

• Rett syndrome is a rare X-linked neurodevelopmental disorder primarily affecting girls.
• It is characterized by normal early development followed by regression, loss of acquired skills, and stereotypical hand movements.
• Mutations in the methyl-CpG binding protein 2 (MECP2) gene are identified in 70-90% of clinically diagnosed Rett syndrome patients.

Observation:

• This study presents three girls with suspected Rett syndrome, exhibiting stereotypical hand movements.
• Patients A and B showed initial normal development, while patient C had severe developmental delay from birth.
• Genetic analysis confirmed MECP2 mutations in patients A and B, supporting the clinical diagnosis.

Findings:

• Patient C, despite presenting with symptoms suggestive of Rett syndrome, carried a neutral variant in the MECP2 gene, not a causative mutation.
• This case underscores that MECP2 mutations explain a spectrum of phenotypes beyond classic Rett syndrome.
• MECP2 mutations can also manifest in boys, with or without Rett syndrome-like features.

Implications:

• The findings highlight the importance of comprehensive genetic testing and differential diagnosis in suspected Rett syndrome cases.
• Understanding the broader phenotypic spectrum associated with MECP2 mutations is crucial for accurate diagnosis and patient management.
• Further research is needed to elucidate the genetic and non-genetic factors contributing to Rett syndrome phenotypes.