Becker Nevus Syndrome

A sporadic syndrome characterized by the presence of a Becker nevus (a late-onset, large, brown birthmark occurring mostly in males that typically develops during childhood or adolescence on the shoulders or upper trunk) in association with unilateral hypoplasia of breast or other cutaneous, muscular, or skeletal defects, all of which usually involve the same side of the body as the nevus. OMIM: 604919

Source last updated 2026-05-24T15:30:00.741Z