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Megalencephaly-capillary malformation-polymicrogyria

What is megalencephaly?capillary malformation-polymicrogyria?

Megalencephaly-capillary malformation-polymicrogyria (MCAP) was first described in 1997 and is characterized by:

  • Macrocephaly (a condition where the head is abnormally large)
  • Cutaneous vascular anomalies
  • Polymicrogyria (a brain malformation indicated by several small brain convolutions).

Additional features include varying degrees of asymmetric somatic overgrowth, distal limb malformations and hyperelasticity. Less than 300 cases have been reported in the literature.

MCAP is also known as macrocephaly-capillary malformation (MCM), to reflect the large brain size, large head size, and polymicrogyria that characterize the syndrome.

Who gets megalencephaly-capillary malformation-polymicrogyria?

MCAP occurs sporadically and affects boys and girls equally without ethnic predilections.

What causes megalencephaly-capillary malformation-polymicrogyria?

Some cases of MCAP have been found to have somatic mutations in phosphatidylinositol-4, the catalytic subunit alpha 5-bisphosphate 3-kinase (PIK3CA) gene in chromosome 3q26.

What are the clinical features of megalencephaly-capillary malformation-polymicrogyria?

These main criteria must be present for MCAP to be diagnosed:

  • Macrocephaly (> 95th percentile) and progressive megalencephaly

  • Capillary malformation.

Minor criteria: variable participation

  • Asymmetric overgrowth
  • Developmental delay
  • Middle line facial capillary malformation
  • Neonatal hypotonia
  • Syndactyly
  • Frontal bulge (rounded prominence of the frontal and parietal bones of the skull)
  • Joint hypermobility
  • Hyperelastic and / or pasty skin.
  • Hydrocephalus
  • Seizures

How is the diagnosis of megalencephaly-capillary malformation-polymicrogyria made?

The diagnosis of MCAP is made on the basis of clinical signs and neuroimaging studies. Both main criteria must be present, with variable minor criteria.

Base magnetic resonance image (Magnetic resonance) of the brain and spine is recommended at the time of diagnosis.

Which is the differential diagnosis for megalencephaly-capillary malformation-polymicrogyria?

MCAP must be distinguished from other vascular malformation overgrowth syndromes including:

  • Skin marmorata telangiectatica congenita
  • Beckwith Weidemann syndrome
  • Proteus syndrome

  • Cloves syndromecongenital, lipomatous, overgrowth, vascular malformations, epidermal nevi and spinal / skeletal and / or abnormalities scoliosis)

  • PTEN hamartoma tumor syndrome

What is the result of megalencephaly-capillary malformation-polymicrogyria?

MCAP patients require ongoing medical surveillance, as well as physical and occupational therapy. Early intervention is helpful in overcoming disability and achieving developmental milestones.

Patients are at increased risk of developing medulloblastoma, meningioma, Wilms tumor, and leukemia throughout his life.

In addition to annual medical exams, all patients must have a cardiology consultation at the time of diagnosis.

Follow-up image recommendations include:

  • MRI of the brain at diagnosis and every 6 months until age 2 years.
  • Abdominal series sonography every 3–6 months for the first 7 years of life.
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