Abnormal dermoepidermal hemidesmosome morphology

What it means

An abnormal structure or appearance of hemidesmosomes, multiprotein complexes that facilitate the stable adhesion of basal epithelial cells to the underlying basement membrane.

Hemidesmosomes (HDs) are highly specialized integrin-mediated epithelial attachment structures that make cells firmly adhere to the extracellular matrix by establishing a link between the underlying basement membrane (BM) and the internal mechanical stress-resilient keratin intermediate filament (IF) network. Although HDs are defined by their ultrastructural appearance, two types of HDs, type I and II, can be distinguished on the basis of their protein components. Classical type I HDs, found in stratified and pseudostratified epithelia, for example in the epidermis, consist in five major components, namely integrin alpha6beta4, plectin isoform 1a (P1a), tetraspanin CD151, bullous pemphigoid antigen (BPAG)1 isoform e (BPAG1e, also called BP230) and BPAG2 (also called BP180 or type XVII collagen). Type II HDs, found in simple epithelia such as that of the intestine, consist of integrin alpha6beta4 and plectin and lack the two BP antigens.

Rare diseases that can present with this1

The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.

Part of the broader category