Microcephaly-Capillary Malformation syndrome is characterized by severe progressive microcephaly, early-onset refractory epilepsy, profound developmental delay, and generalized capillary malformations. The capillary malformations, sometimes referred to as port wine stains, are spread diffusely throughout the body. Other less common features can include hypoplasia of the distal phalanges and of the fingers and toes, mild heart defects, and dysmorphic facies.
Mutations of the STAMBP gene have been identified in patients with MIC-CAP. McDonnell et al., identified six missense variants, two nonsense mutations, two translational frameshift mutations and three intronic mutations, in a total of 10 patients with MIC-CAP. STAMBP is involved with endosomal sorting and trafficking machinery and functions in the regulation of sorting of endosomal sorting complexes required for transport (ESCRTs) machinery and ubiquitinated receptor cargo.