- Cutaneous photosensitivity (HP:0000992): An increased sensitivity of the skin to light. Photosensitivity may result in a rash upon exposure to the sun (which is known as photodermatosis). Photosensitivity can be diagnosed by phototests in which light is shone on small areas of skin. Evidence: TAS. Frequency: 0/1. (PMID:31374204)
- Ichthyosis (HP:0008064): An abnormality of the skin characterized the presence of excessive amounts of dry surface scales on the skin resulting from an abnormality of keratinization. Evidence: PCS. Frequency: 1/2. (PMID:31374204)
- Brittle hair (HP:0002299): Fragile, easily breakable hair, i.e., with reduced tensile strength. Evidence: PCS. (PMID:31374204)
- Autosomal recessive inheritance (HP:0000007): A mode of inheritance that is observed for traits related to a gene encoded on one of the autosomes (i.e., the human chromosomes 1-22) in which a trait manifests in individuals with two pathogenic alleles, either homozygotes (two copies of the same mutant allele) or compound heterozygotes (whereby each copy of a gene has a distinct mutant allele). Evidence: PCS. (PMID:31374204)
- Tiger tail banding (HP:0045055): An abnormal appearance of hair under polarizing microscopy (using crossed polarizers), whereby hair shafts show striking alternating bright and dark bands, often referred to as tiger tail banding. Evidence: PCS. Frequency: 2/2. (PMID:31374204)
- Congenital nonbullous ichthyosiform erythroderma (HP:0007479): The term collodion baby applies to newborns who appear to have an extra layer of skin (known as a collodion membrane) that has a collodion-like quality. It is a descriptive term, not a specific diagnosis or disorder (as such, it is a syndrome). Affected babies are born in a collodion membrane, a shiny waxy outer layer to the skin. This is shed 10-14 days after birth, revealing the main symptom of the disease, extensive scaling of the skin caused by hyperkeratosis. With increasing age, the scaling tends to be concentrated around joints in areas such as the groin, the armpits, the inside of the elbow and the neck. The scales often tile the skin and may resemble fish scales. Evidence: PCS. (PMID:31374204)
- Follicular hyperkeratosis (HP:0007502): A skin condition characterized by excessive development of keratin in hair follicles, resulting in rough, cone-shaped, elevated papules resulting from closure of hair follicles with a white plug of sebum. Evidence: PCS. (PMID:31374204)
These phenotypes are associated with the disease trichothiodystrophy 7, nonphotosensitive (OMIM:618546).