- Increased cellular sensitivity to UV light (HP:0003224, a Human Phenotype Ontology term). Evidence: PCS. (PMID:19329487)
- Cutaneous photosensitivity (HP:0000992, a Human Phenotype Ontology term): 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: PCS. Frequency: 1/1. (PMID:19329487)
- Freckling (HP:0001480, a Human Phenotype Ontology term): The presence of an increased number of freckles, small circular spots on the skin that are darker than the surrounding skin because of deposits of melanin. Evidence: PCS. Frequency: 1/1. (PMID:19329487)
- Abnormal circulating porphyrin concentration (HP:0010472, a Human Phenotype Ontology term): Any deviation from the normal concentration of porphyrins in the blood circulation. Evidence: PCS. Frequency: 0/1. (PMID:19329487)
- Infantile onset (HP:0003593, a Human Phenotype Ontology term): Onset of signs or symptoms of disease between 28 days to one year of life. Evidence: PCS. Frequency: 1/1. (PMID:19329487)
- Autosomal recessive inheritance (HP:0000007, a Human Phenotype Ontology term): 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:19329487)
These phenotypes are associated with the disease UV-sensitive syndrome 2 (OMIM:614621, an entry in Online Mendelian Inheritance in Man).