1. ^*Laboratory of Molecular Dermatology, Department of Dermatology, Rambam Medical Center, Haifa, Israel
2. ^†Biotechnology Interdisciplinary Unit, Israel Institute of Technology, Haifa, Israel
3. ^‡Computer Science Department, Israel Institute of Technology, Haifa, Israel
4. ^§Dermatology Unit, Western Galile Hospital, Naharya, Israel
5. ^¶Bruce Rappaport Faculty of Medicine, Technion, Israel Institute of Technology, Haifa, Israel

Correspondence: Eli Sprecher, MD, PhD, Laboratory of Molecular Dermatology, Department of Dermatology, Rambam Medical Center, Haifa, Israel. Email: e_sprecher@rambam.health.gov.il

Received 1 February 2005; Revised 2 March 2005; Accepted 3 March 2005.

Abstract

Congenital recessive ichthyoses represent a vast and markedly heterogeneous group of diseases that have been mapped to at least seven distinct chromosomal loci. In this study, we ascertained two consanguineous families presenting with congenital ichthyosis. Using homozygosity mapping, we identified a 6.5 cM homozygous region on 12p11.2–q13 shared by all affected individuals. Multipoint logarithm of odds ratio (LOD) score analysis placed the new locus between markers D12S345 and D12S390 with a maximum LOD score of 4.79 at marker CH12SSR13. This region harbors PPHLN1, encoding periphilin 1, a protein involved in the cornification process. No deleterious mutations were identified within the coding region of this gene, suggesting the existence of another gene associated with epidermal differentiation on 12p11.2–q13.