Megalencephaly-capillary malformation syndrome

Parents should notice an unusually large head circumference at birth, rapid head growth in the first months, and pink or red skin spots—especially on the face—that may form a net‑like pattern. If the baby also has a soft, stretchable skin texture or mild limb overgrowth, a pediatrician may consider MCAP and order a head‑circumference growth chart and a skin examination. How is MCAP confirmed and what genetic tests are required?::Diagnosis starts with a detailed physical exam and imaging studies such as MRI to assess brain size and structure. A skin biopsy or blood sample is then sent for next‑generation sequencing targeting the PIK3CA gene. Because the mutation is mosaic, multiple tissue samples (e.g., skin, blood, buccal cells) increase the chance of detection. What are the main treatment options for seizures and hydrocephalus in children with MCAP?::Seizure management follows standard epilepsy protocols: antiepileptic drugs like levetiracetam or valproate, with adjustments based on EEG findings. Hydrocephalus is usually treated with a ventriculoperitoneal shunt; however, shunt placement may need to be repeated if overgrowth causes increased pressure. Multidisciplinary care—including neurology, neurosurgery, and developmental specialists—is essential. Can parents reduce the risk of MCAP in future pregnancies and what counseling is available?::MCAP results from a de novo, mosaic mutation, so the risk for another child is low but not zero. Prenatal testing via chorionic villus sampling or amniocentesis can screen for PIK3CA mutations, though mosaicism may limit detection. Genetic counseling can discuss recurrence risk, options for preimplantation genetic diagnosis, and the benefits of early neonatal screening.