Elastosis perforans serpiginosa-like pseudoxanthoma elasticum in a child with severe Moya Moya disease

A 2-year-old girl with Moya Moya disease who had relapsing cerebrovascular strokes presented with loose skin folds, 'chicken' skin appearance and perforating elastosis serpiginosa-like lesions in the genitocrural region. Histologically, calcified material perforating the epidermis and adjacent short curled and mineralized elastic fibres suggested a variant of pseudoxanthoma elasticum (PXE). As PXE is known to be caused by various mutations in the transmembrane transporter ABCC6 gene, we hypothesized that a novel ABCC6 mutation may underlie this unique combination of PXE and elastopathic vascular damage. Therefore, the complete ABCC6 coding region of the patient and her parents was screened for genetic alterations. No bona fide disease-causing mutation of ABCC6 could be found in the child and in her parents. However, two novel allelic amino acid substitutions (Arg1273Lys and Glu1293Lys; exon 27) were found in the girl and her father, localized in close proximity to the region that codes for the functionally critical second nucleotide-binding fold of ABCC6. Although a causal involvement of these amino acid substitutions could not be proven based on this study, both heterozygote substitutions may possibly have interacted with other undetected recessive maternal ABCC6 changes in the child. To the best of our knowledge, this is the first report of an association between early-onset PXE and severe Moya Moya syndrome possibly related to ABCC6 changes.