Neonatal Med.  2023 May;30(2):55-59. 10.5385/nm.2023.30.2.55.

A Neonate Diagnosed with Megalencephaly-Capillary Malformation-Polymicrogyria Syndrome with PIK3CA Mutation

• Park YM
• Kim YM
• Oh SH
• Jin HS

• KMID: 2542548
• DOI: http://doi.org/10.5385/nm.2023.30.2.55

Abstract

Megalencephaly-capillary malformation-polymicrogyria syndrome (MCAP) is a rare genetic disorder characterized by megalencephaly, polymicrogyria, body overgrowth, and cutaneous capillary malformations. It has been reported recently that MCAP is related to a somatic mosaic mutation in the phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) gene. We report a case of hemimegalencephaly with polymicrogyria and cutaneous capillary malformations diagnosed by genetic evaluation of MCAP in the neonatal period. The PIK3CA mutation [c.1635G>T (p. Glu545Asp)] was determined by Sanger sequencing. The patient was treated with a ventriculoperitoneal shunt for progressive hydrocephalus. Because of the dynamic, progressive clinical manifestations and tumor-prone traits of MCAP, early diagnosis is important. Moreover, since the phosphoinositide 3-kinase (PI3K)-specific inhibitor, a targeted therapy for the PI3K/AKT/mTOR signaling pathway is emerging as a new therapy, early genetic diagnosis is becoming increasingly important.

Keyword

PIK3CA; Megalencephaly; Cutaneous vascular malformation; Polymicrogyria

Figure

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  Figure 1. (A) Physical features of the newborn showing midfacial capillary malformation of the lip and philtrum. (B) The reticulated port-wine stain is extensive on the trunk and extremities.

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  Figure 2. Brain magnetic resonance imaging. (A) Hemimegalencephaly and polymicrogyria (arrow) in the left frontoparietal lobe were shown at birth, and (B, C) hydrocephalus and ectopic cerebellar tonsils (arrow) were detected at 7 months.

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