Features include always present findings: Lamina lucida cleavage, Onychogryphosis, Abnormal blistering of the skin, and Urethral stenosis and others; and common findings: Absent axillary hair and Absent pubic hair. 12 total HPO annotations.

ITGB4 encodes integrin subunit beta 4 (1,822 aa). Integrin alpha-6/beta-4 is a receptor for laminin. Plays a critical structural role in the hemidesmosome of epithelial cells. Is required for the regulation of keratinocyte polarity and motility. Highest expression in Nerve Tibial (362.3 TPM) and Skin Sun Exposed Lower leg (180.1 TPM).

Epidermolysis bullosa, junctional 5A, intermediate is associated with mutations in the ITGB4 gene on chromosome 17.

The ITGB4 protein participates in Keratinocyte stem cell differentiates into transit amplifying cell in the basal layer of interfollicular epidermis, Mammary stem cell produces myoepithelial/basal progenitor, and Embryonic ectoderm cell produces mammary stem cell pathways.

ITGB4 is classified as a druggable target (Cell Surface and Druggable Genome categories) with score 0.0.

Genetic testing for ITGB4 is available. Testing is considered confirmatory for diagnosis.

Phenotype severity distribution: 9 always present features, 2 common features.