MECP2 mutation in non-fatal, non-progressive encephalopathy in a male

Area of Science:

• Genetics
• Neurology
• Molecular Biology

Background:

• Rett syndrome (RTT) and Angelman syndrome (AS) are neurodevelopmental disorders with overlapping clinical features.
• Genetic mutations in MECP2 and UBE3A are primary causes of RTT and AS, respectively.
• Diagnostic challenges arise due to clinical similarities and the need for precise genetic identification.

Purpose of the Study:

• To investigate the clinical overlap between Rett syndrome and Angelman syndrome.
• To screen the MECP2 gene in patients with a suspected Angelman syndrome diagnosis but normal UBE3A methylation.
• To determine if MECP2 mutations contribute to phenotypes mimicking Angelman syndrome.

Main Methods:

• Genetic screening of the MECP2 gene.
• Analysis of a cohort of 78 patients with a possible Angelman syndrome diagnosis.
• Assessment of UBE3A locus methylation patterns.

Main Results:

• MECP2 mutations (missense, nonsense, frameshift) were identified in 6 out of 78 patients.
• Four female cases presented with MECP2 mutations consistent with Rett syndrome.
• One female and one male case exhibited severe encephalopathy with MECP2 mutations, expanding the clinical spectrum.

Conclusions:

• MECP2 gene mutations can present with a wide range of clinical symptoms, including those resembling Angelman syndrome.
• The findings suggest that MECP2 gene screening is crucial for patients with severe encephalopathy, irrespective of sex.
• This study underscores the importance of considering MECP2 mutations in the differential diagnosis of neurodevelopmental disorders.