FLG and ichthyosis vulgaris: Palmar and plantar hyperlinearity is a consistent clinical finding in the monogenic FLG disease ichthyosis vulgaris, and in keeping with a semidominant trait, intermediate hyperlinearity is thought to be associated with heterozygosity for FLG mutations; hyperlinearity has been associated as a significant finding in patients with FLG-related AD.37-40 Brown et al41 have recently shown significant association of palmar hyperlinearity with FLG-null mutations in a population-based cohort.41