FREM3 (FRAS1-related extracellular matrix protein 3) is an extracellular matrix (ECM) protein that localises at the fetal and adult epithelial basement membrane []. It may function independently from other ECM proteins, such as Fras1, Frem1 and Frem2 [].
FREM1 (FRAS1-related extracellular matrix protein 1) is an extracellular matrix protein that forms a ternary complex in the basement membrane with FRAS1 and FREM2 during epidermal development []. FREM1 also appears to act as a dermal mediator of basement membrane adhesion independently of the FRAS1 []. Mutations in the FREM1 gene cause two rare syndromes - bifid nose with or without anorectal and renal anomalies syndrome (BNAR; OMIM #608980) and Manitoba oculotrichoanal syndrome (MOTA; OMIM #248450) - whose phenotypic characteristics overlap those seen in individuals with Fraser syndrome [].
