ichthyosis—congenital—autosomal recessive 5
Definition An autosomal recessive form of (OMIM:604777) congenital ichthyosis*.
*A disorder of keratinisation with abnormal differentiation and desquamation of the epidermis, resulting in abnormal skin scaling over the whole body.
Main ichthyosis phenotypes
• Lamellar ichthyosis A condition in which the infant is encased in a collodion-like membrane at birth; skin scales develop later and cover the entire body.
• Non-bullous congenital ichthyosiform erythroderma A condition characterised by fine whitish scaling on an erythrodermal background; larger brownish scales are present on the buttocks, neck and legs.
Note: Phenotypic overlaps occur in the same patient or among patients from the same family.
Molecular pathology Defects of CYP4F22, which encodes a cytochrome P450 enzyme, cause ichthyosis—congenital—autosomal recessive 5.
Synonyms Ichthyosis congenita III, ichthyosis—nonlamellar and nonerythrodermic—congenital—autosomal recessive, ichthyosis—lamellar—3, lamellar ichthyosis