Non-bullous congentital ichthyosiform erythroderma associated with homozygosity for a novel missense mutation in an ATP binding domain of ABCA12.

[harlequin ichthyosis]

A Mutations in the gene encoding the ABCA 12 protein are associated with different subtypes of autosomal recessive congenital ichthyosis (ARCI ), including Harlequin ichthyosis (HI ), lamellar ichthyosis (LI ) and non-bullous congenital ichthyosiform erythroderma (NCIE ). Disruption of ABCA 12 lead to perturbed lipid transport in lamellar granules and a defective intercellular lipid layer of the stratum corneum . We have identified a large consanguineous Pakistani family affected by NCIE . Autozygosity mapping showed that affected individuals are homozygous for the ABCA 12 gene region . Subsequent mutation screening revealed a homozygous c .4676 G >T transition in all five affected family members . The mutation results in a novel p .G 1559 V substitution within the first nucleotide binding domain of ABCA 12 . The combined results support that an ABCA 12 missense mutation , despite its location in a functional domain , may be associated with a mild ichthyosis phenotype . Furthermore , our findings increase the mutational spectrum in ABCA 12 associated with ARCI of diagnostic and prognostic importance .