Netherton syndrome (NS, OMIM #256500) is a rare autosomal recessive disease characterized by a triad of congenital ichthyosiform erythroderma (CIE) or ichthyosis linearis circumflexa (ILC), trichorrhexis invaginata (TI), and atopic predisposition. The disease is caused by a mutation in the SPINK5 gene (serine protease inhibitor of Kazal type 5) encoding LEKTI (lymphoepithelial Kazal type-related inhibitor). We performed whole-exome sequencing on one Chinese NS family and made genotype-phenotype correlation analysis on the patients clinically diagnosed with NS or congenital ichthyosis erythroderma. We identified a novel frameshift mutation c.2474_2475del (p.Glu825Glyfs*2) in the SPINK5 gene. The N-terminal mutations of LEKTI cause a severer phenotype, while the C-terminal mutations of LEKT1 are related to a milder phenotype. Our findings suggest that Netherton syndrome may be underestimated clinically, and our findings further expand the reservoir of SPINK5 mutations in Netherton syndrome.

BACKGROUND: Congenital ichthyosiform erythroderma (CIE ) is characterized by fine, whitish scales on a background of erythematous skin over the whole body; it is reportedly caused by mutations in ABCA12, ALOX12B, ALOXE3, CERS3, CYP4F22, NIPAL4, PNPLA1, and TGM1 genes.
METHODS: A 15-month-old girl presented with CIE associated with compound heterozygous ABCA12 mutations, a known missense mutation c.4139A>G (p.Asn1380Ser) from her father, and a novel missense mutation c.4300A>G (p.Thr1434Ala) from her mother.
CONCLUSIONS: This is the first report to indicate that compound heterozygous missense mutations in the first ATP-binding cassette of ABCA12 could contribute to the onset of CIE.