Ichthyosiform changes in a patient with RAC1 mutation.

RAS-related C3 Botulinum Toxin Substrate 1 (RAC1) is a Rho GTPase that modulates numerous cellular functions including transcriptional regulation and actin-based structure turnover. Reported de novo RAC1 mutations are rare but generally manifest in developmental delay and brain malformations. In Rac1 knockout mice, a hairless phenotype has been observed, but little is known of other cutaneous phenotypes of RAC1 mutations. In this report, we describe the first known case of a RAC1 mutation with ichthyosiform changes.