A severe <scp> <i>ABCC6</i> </scp> ‐induced generalized arterial calcification of infancy overshadowed by the <scp> <i>EGFR</i> </scp> ‐associated neonatal inflammatory skin and bowel disease 2 in a Roma girl

Neonatal inflammatory skin and bowel disease 2 is an epidermal growth factor receptor (EGFR)-associated autosomal recessive early-infantile disease with inflammatory skin, alopecia, progeroid features, electrolyte imbalance, recurrent infections, and premature death. Pseudoxanthoma elasticum (PXE) is another autosomal recessive skin disorder with some ocular and cardiovascular alterations, caused by variations in the ATP binding cassette subfamily c member 6 (ABCC6) gene. However, ABCC6-deficiency is, rarely, also presented as as an early/late-infantile autosomal recessive generalized arterial calcification of infancy. In this case report we present the known homozygous EGFR p.G428D and the compound heterozygous ABCC6 p.R518* and p.R1221H variations in a 7-month-old Roma girl from a consanguineous family, who developed a combined EGFR/ABCC6-associated phenotype and died at 10 months of age. This case report and data in literature led us to conclude, that (1) EGFR-associated disease, with a serious early-infantile skin manifestation and occasional cardiovascular defects, may clinically overshadow other similar diseases such as generalized arterial calcification of infancy, if the single-gene/variant sequencing is used for diagnostics. (2) This probability increases if the person under investigation comes from a consanguineous family, and (3) the presented biallelic EGFR variation may be a co-factor of PXE severity. However, more analyses are required to make this conclusion definitive.