PIK3CA-Related Overgrowth Spectrum: Exploring brain growth from fetus to infant.

Background: Megalencephaly-capillary malformation-polymicrogyria syndrome (MCAP) is a rare neurological disorder characterized by abnormal brain size, vascular malformations, and body overgrowth. MCAP is caused by somatic mosaicism of PIK3CA, a crucial gene in regulation of cell growth and survival, and is one of the disorders in the PIK3CA-related overgrowth spectrum.

Methods: We present a unique clinical report of a male infant diagnosed with MCAP from prenatal stages to age 12 months. Prenatal imaging unveiled ventricular asymmetry, later confirmed postnatally as megalencephaly. Genetic analysis identified a PIK3CA mutation. The patient underwent early interventions, including ventriculoperitoneal shunt placement and posterior fossa decompression.

Results: Despite early interventions, the patient developed progressive macrocrania, hydrocephalus, and significant neurodevelopmental delay. Multidisciplinary management and continuous neuroimaging were crucial in addressing complications associated with the disorder.

Conclusions: This case underscores the critical need for multidisciplinary care and continual neuroimaging surveillance to effectively navigate the progressive complications associated with PIK3CA-related overgrowth spectrum. The diagnostic hurdles and management challenges intrinsic to the disorder's natural course are elucidated. Although current treatments manage symptoms, emerging therapies hold promise for improving patient outcomes.