RESUMEN
BACKGROUND: Collodion phenotype is a term applied to the condition affecting a newborn involving a parchmentlike membrane covering the whole body surface (collodion membrane). This presentation is common to several different forms of autosomal recessive congenital ichthyoses, including nonbullous congenital ichthyosiform erythroderma (NCIE), lamellar ichthyosis (LI), and harlequin ichthyosis (HI). Recent years have seen considerable advances in our understanding of the molecular basis of autosomal recessive forms of congenital ichthyosis. Several genetic loci have been identified for LI and NCIE. OBSERVATIONS: We describe the clinical and molecular features of 2 cases of self-healing newborns of collodion phenotype developing mild NCIE. A dramatic improvement of the skin was observed in the first few weeks after birth in both cases. The molecular analysis of the ALOX12B gene demonstrated that both patients were compound heterozygous for previously unreported mutations. CONCLUSIONS: Both patients were compound heterozygous for novel ALOX12B mutations, underscoring the concept that mutations in at least 2 different genes, ALOX12B and TGM1, may result in this unusual clinical phenotype.