Core clinical features that are present in most reported individuals include flexion contractures, developmental delay (DD) and motor symptoms. Contractures are the most prominent feature in reported cohort, involving both upper and lower limbs, with multiple joints affected in most individuals, consistent with a descriptive diagnosis of arthrogryposis multiplex congenita. Additional joint deformities include abnormalities of the spinal curvature such as kyphosis or scoliosis as well as defects of hip formation, including congenital hip dislocation (CHD) and developmental dysplasia of the hip (DDH).
Developmental delay with variable severity was present in all published cases with available information (79% of individuals) and rated as global developmental delay (GDD) in 56%. ID, present in 53%, was described as mild in 18%, moderate to severe in 25% and not further specified in 10% of individuals. Behavioral problems were reported in 19%, mostly not further specified, but in some cases described as hyperactivity, anxiety and aggressive or impulsive behaviors.
A detailed assessment of facial features in previously published cases with available photographs showed a broad range of dysmorphic signs. The most prevalent included a broad/full nasal tip (95.8%), narrowing of the forehead (79.2%) and full cheeks (70.8%). Further characteristic features encompassed highly arched eyebrows (37.5%), unilateral or bilateral ptosis (37.5%), thick/full vermilion of the lower lip (41.7%), a broad, tall or pointed chin (45.8%), a small, narrow mouth (29.2%) and retrognathia (29.2%).