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Updated: Oct 8, 2025
Testing Sensory and Multisensory Function in Children with Autism Spectrum Disorder
Published on: April 22, 2015
Autism spectrum disorder in a child with megalencephaly-capillary malformation-polymicrogyria syndrome (MCAP)
1School of Medical Sciences, University of Manchester, Manchester University NHS Foundation Trust, Manchester, Greater Manchester, UK lilystjohn98@gmail.com.
Abstract:
Megalencephaly-capillary malformation-polymicrogyria syndrome (MCAP) is a rare disorder that arises as a result of a somatic mosaic mutation in the PIK3CA gene. It characteristically presents with postnatal or congenital megalencephaly, cutaneous capillary malformations, postaxial polydactyly and often segmental or focal body overgrowth. We report a 7-year-old boy with known MCAP who was diagnosed at around 10 months old with a mosaic change in the PIK3CA gene. He was found to have hall-mark clinical signs; macrocephaly and four-limb postaxial polydactyly. Since diagnosis, he has had multiple clinical features, most of which typically present in children with MCAP. He has now been diagnosed with autism spectrum disorder (ASD), demand avoidance and is under assessment for attention deficit hyperactivity disorder. Although some cases have been raised to the M-CM Network, to our knowledge this is the first case of ASD in MCAP to be reported in the literature.
Insights
Megalencephaly-capillary malformation-polymicrogyria syndrome (MCAP), a PIK3CA-related disorder, can be associated with autism spectrum disorder (ASD). This report details the first known case of ASD in a child with MCAP.
Area of Science:
- Genetics
- Neurology
- Pediatrics
Background:
- Megalencephaly-capillary malformation-polymicrogyria syndrome (MCAP) is a rare genetic disorder.
- It is caused by somatic mosaic mutations in the PIK3CA gene.
- MCAP typically presents with megalencephaly, capillary malformations, and polydactyly.
Observation:
- A 7-year-old boy with diagnosed MCAP presented with characteristic features including macrocephaly and polydactyly.
- He developed additional clinical features over time, consistent with MCAP.
- The patient was diagnosed with autism spectrum disorder (ASD) and demand avoidance, with further assessment for attention deficit hyperactivity disorder.
Findings:
- This case represents the first documented instance of autism spectrum disorder (ASD) in an individual with Megalencephaly-capillary malformation-polymicrogyria syndrome (MCAP).
- The PIK3CA gene mutation underlies MCAP and may influence neurodevelopmental outcomes.
Implications:
- This finding expands the known clinical spectrum of MCAP.
- Further research is needed to understand the link between PIK3CA mutations and neurodevelopmental disorders like ASD.
- Early recognition of potential neurodevelopmental comorbidities in MCAP is crucial for timely intervention.
