Four genetic disorders of keratinization are known to have a structural defect of tonofibrils. In the Curth-Macklin form of ichthyosis hystrix (IHCM), concentric unbroken shells of abnormal tonofilaments form around the nucleus. IHCM is caused by heterozygous mutation in the KRT1 gene (139350) on chromosome 12q13. (OMIM)
Ichthyosis Prematurity Syndrome
Ichthyosis Tapered Fingers Midline Groove Up
ichthyosis vulgaris +
Ichthyosis, Mental Retardation, Dwarfism, and Renal Impairment
Ichthyosis, Spastic Quadriplegia, and Mental Retardation
Ichthyosis, Split Hairs, and Amino Aciduria
Ichthyosis-Mental Retardation Syndrome with Large Keratohyalin Granules in the Skin
ICHTHYOTIC KERATODERMA, SPASTICITY, HYPOMYELINATION, AND DYSMORPHIC FACIAL FEATURES