Table 1. Synopsis of the MCAP an Noonan phenotypes.

MCAP phenotype	Noonan phenotype
Segmental overgrowth	Facial dysmorphism
(hemi-)megalencephalya	Epicanthal folds
Cerebellar tonsillar ectopia or Chiari malformation	Ptosis
Abnormal thick (mega-) corpus callosum	Down-slanting palpebral fissures
Congenital somatic overgrowth	Triangular facies low set and/or posteriorly rotated ears
Somatic or cranial asymmetry	Ophthalmologic
	Strabismus, myopia
Vascular disorders
Cutaneous capillary malformationsa (e.g., midline facial nevus flammeus, hemangiomata, cutis marmorata)	Hearing lossDental/oral features
Digital anomalies	Cardiovascular features
Syndactylya	Congenital heart defects (various)
Postaxial polydactyly	Webbed and short neck with low posterior hair line
Cortical brain malformations
Polymicrogyria	Feeding difficulties
Connective tissue dysplasia	Developmental delay
Skin hyperelasticitya
Joint hypermobilitya	Skeletal features
Thick, soft subcutaneous tissuea
Othersb	Cryptorchism
Hypotonia
Developmental delay	Lymphatic features
Fronal bossing Seizures	Lymphedema, lymphangiectasia
	Hematological features
	Bleeding diathesis
	Leukemia

Abbreviation: MCAP, megalencephaly-capillary malformation.

^aMCAP: these items are considered ‘major criteria', whereas the other items are considered ‘supportive criteria'.

^bThe other findings are considered to be ‘secondary'. Italics: our patient complied with these criteria.

Adapted from Mirzaa et al⁵ and Tartaglia et al.¹¹ Although some symptoms of the Noonan phenotype are present in our index patient, the MCAP phenotype is much more distinctive.