Kniest-Like Dysplasia With Pursed Lips And Ectopia Lentis

Clinical Features

Burton et al. (1986) described a skeletal dysplasia in 2 sibs, a male and female. The clinical and x-ray features resembled those observed in Kniest dysplasia (156550) and in Rolland-Desbuquois syndrome (see 224400) but important differences were noted, specifically, microstomia, pursed lips, and ectopia lentis. Histologically, scattered, dense patches consisting of collagen fibers 10 to 30 times broader than normal were seen throughout the cartilage matrix; the 'Swiss cheese' appearance characteristic of Kniest dysplasia was not observed. The lenses were dislocated downward in both patients. The parents were not related. The mouth resembled that of the whistling face syndrome (277720) but other features were different.

Lo et al. (1998) reported this disorder in a 2-year-old girl with characteristic clinical findings of short stature, joint stiffness, microstomia, and pursed lips. Platyspondyly with cervical kyphosis, but no coronal clefts, and bowing of the long bones were distinctive radiographic findings.

Spranger et al. (2000) restudied the sister and brother (then teenagers) reported by Burton et al. (1986). Both had developed severe myotonia and characteristic facial and skeletal features of Schwartz-Jampel syndrome (SJS1; 255800). The disorder in the sibs mapped to the SJS1 locus on chromosome 1p34-p36, supporting the claim that they had SJS1. Spranger et al. (2000) suggested that Burton disease may not exist as a nosologic entity.