Nagashima-Type Palmoplantar Keratosis with Compound Heterozygous Mutations in SERPINB7

Abstract

Nagashima-type palmoplantar keratosis (NPPK) is a diffuse, non-syndromic (isolated), autosomal recessive palmoplantar keratoderma (PPK) with transgredients. It is characterized by non-progressive mild to moderate transgredient PPK. The mutation in <i>SERPINB7</i> is reported to underlie the condition. Though many case reports/series have demonstrated various mutations in <i>SERPINB7</i>, the genotype-phenotype correlation in this disorder is still lacking. We herein report two brothers with NPPK. Both patients were found to be compound heterozygous for c.796C&#x3e;T and c.650_653delCTGT in the <i>SERPINB7</i> gene. We then summarize the previously reported cases of different mutations in <i>SERPINB7</i> along with their clinical phenotypes in an attempt to shed some light on this correlation. Further investigations and systematic data collection are still needed to clarify this issue.