Extracellular matrix protein that plays a role in epidermal differentiation and is required for epidermal adhesion during embryonic development. Defects in FREM1 are the cause of bifid nose with or without anorectal and renal anomalies (BNAR). A bifid nose is a rare congenital deformity due to failure of the paired nasal processes to fuse to a single midline organ during early gestation. BNAR is an autosomal recessive disorder and patients usually present a bifid nose associated with renal and anorectal malformations. Defects in FREM1 are the cause of Manitoba oculotrichoanal syndrome (MOTA). MOTA is a rare condition defined by eyelid colobomas, cryptophthalmos, and anophthalmia/microphthalmia, an aberrant hairline, a bifid or broad nasal tip, and gastrointestinal anomalies such as omphalocele and anal stenosis. Defects in FREM1 are the cause of trigonocephaly type 2 (TRIGNO2). TRIGNO2 is a keel-shaped deformation of the forehead, caused by premature fusion of the metopic sutures. It results in a triangular shape of the head. Belongs to the FRAS1 family. 4 isoforms of the human protein are produced by alternative splicing. Note: This description may include information from UniProtKB.