Novel mutations in ALOX12B in patients with autosomal recessive congenital ichthyosis and evidence for genetic heterogeneity on chromosome 17p13.

We report clinical and molecular findings in 20 patients from 11 families with autosomal recessive congenital ichthyosis (ARCI) linked to chromosome 17p13, and attributed to mutations in the ALOX gene cluster, which includes three lipoxygenase genes, ALOXE3, ALOX12B, and ALOX15B. We identified six novel missense mutations and one novel deletion leading to a premature stop codon in ALOX12B in only six out of the 11 families which led us to investigate a possible implication of ALOX15B. Mutation analysis of this gene, as well as ALOXE3, which is known to be mutated in some cases of ARCI, failed to reveal causative mutations in the five remaining ARCI families, indicating that other genes on chromosome 17p13 may be involved in this disease. However, by adding new variants to the repertoire of ALOX12B mutations in non-bullous congenital ichthyosiform erythroderma, our data contribute to an enlargement of the spectrum of mutations for the development of efficient molecular genetic tests for analysis of at risk individuals whose carrier status is unknown.