[Rett phenotype in patient with XXY karyotype: case report]

Area of Science:

• Genetics
• Neurodevelopmental Disorders
• Pediatric Neurology

Background:

• Rett syndrome is a neurodevelopmental disorder typically affecting girls, characterized by specific motor and cognitive impairments.
• XYY syndrome (47,XYY) is a chromosomal condition in males associated with certain physical and behavioral traits, but not typically severe neurodevelopmental regression.

Observation:

• A male infant with an XYY karyotype presented with early-onset progressive neurological decline starting around 11 months of age.
• Clinical manifestations included developmental stagnation, regression, microcephaly, and characteristic stereotypic hand movements with loss of purposeful hand use.
• Extensive investigations ruled out common systemic or neurological etiological factors.

Findings:

• The patient exhibited a phenotype strikingly similar to Rett syndrome, a condition not previously associated with XYY karyotype.
• This case suggests a potential overlap or novel presentation of neurodevelopmental disorders in individuals with chromosomal abnormalities.

Implications:

• This case expands the known phenotypic spectrum associated with XYY syndrome.
• It raises questions about the genetic and etiological factors underlying neurodevelopmental disorders that mimic Rett syndrome.
• Further research is warranted to explore the interaction between chromosomal alterations and neurodevelopmental trajectories.