- Congenital onset (HP:0003577): A phenotypic abnormality that is present at birth. Evidence: PCS. Frequency: 4/4. (PMID:18219278;PMID:19474805;PMID:16505000)
- Hypergranulosis (HP:0025114): Hypergranulosis is an increased thickness of the stratum granulosum. Evidence: PCS. Frequency: 2/2. (PMID:16505000)
- Generalized hyperkeratosis (HP:0005595). Evidence: PCS. Frequency: 2/2. (PMID:16505000)
- Epidermal acanthosis (HP:0025092): Diffuse hypertrophy or thickening of the stratum spinosum of the epidermis (prickle cell layer of the skin). Evidence: PCS. Frequency: 4/4. (PMID:18219278;PMID:19474805;PMID:16505000)
- Cobblestone-like hyperkeratosis (HP:0031288): The presence of verrucous, cobblestone-like papules and nodules in a region of skin that is said to have an appearance like that of cobblestones. Evidence: PCS. Frequency: 1/2. (PMID:16505000)
- Orthokeratosis (HP:0040162): Formation of an anuclear keratin layer. Evidence: PCS. Frequency: 1/1. (PMID:18219278)
- Keratinocyte vacuolization (HP:0034703): Increased number of vacuoles (membrane-bound organelles that areempty of cytoplasm, lined with a membrane, and filled with fluid) in keratinocytes. Evidence: PCS. Frequency: 2/2. (PMID:16505000)
- Abnormal blistering of the skin (HP:0008066): The presence of one or more bullae on the skin, defined as fluid-filled blisters more than 5 mm in diameter with thin walls. Evidence: PCS. Frequency: 2/4. (PMID:18219278;PMID:19474805;PMID:16505000)
- Hypernatremic dehydration (HP:0004906). Evidence: PCS. Frequency: 1/4. (PMID:18219278;PMID:19474805;PMID:16505000)
- Erythroderma (HP:0001019): An inflammatory exfoliative dermatosis involving nearly all of the surface of the skin. Erythroderma develops suddenly. A patchy erythema may generalize and spread to affect most of the skin. Scaling may appear in 2-6 days and be accompanied by hot, red, dry skin, malaise, and fever. Evidence: PCS. Frequency: 3/3. (PMID:18219278;PMID:16505000)
- 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:16505000)
- 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. Frequency: 3/4. (PMID:18219278;PMID:19474805;PMID:16505000)
- Palmoplantar keratoderma (HP:0000982): Abnormal thickening of the skin of the palms of the hands and the soles of the feet. Evidence: PCS. Frequency: 0/4. (PMID:18219278;PMID:19474805;PMID:16505000)
These phenotypes are associated with the disease epidermolytic hyperkeratosis 2B, autosomal recessive (OMIM:620707).