[Case report: Scapular asymmetry caused by congenital unilateral absence of trapezius]. / Asimetría escapular por agenesia congénita de trapecio unilateral: a propósito de un caso.

Congenital unilateral absence of trapezius is a rare condition, previously reported in cadaveric specimens. It can cause static shoulder asymmetry and affects the scapular biomechanics and functionality, so complete physical examination of the patient becomes important in order to dimiss or suspect an anomaly. We present a case of a 8 years old boy with asymmetry and scapular winging, who was referred to rehabilitation, suspected facioscapulohumeral dystrophy. An MRI scan of cervical spine and shoulder confirmed the absence of the right trapezius muscle. There were no functional disabilities. No other significant congenital anomalies were found.