Pyle Disease

A rare bone dysplasia characterized by genu valgum, metaphyseal anomalies with broadening of the long bones extending into the diaphyses and giving the femora and tibiae an Erlenmeyer flask'' appearance, widening of the ribs and clavicles, platyspondyly and cortical thinning.

Epidemiology

To date, less than 30 cases have been reported in the literature.

Clinical description

Cranial involvement is minimal with mild hyperostosis of the skull base, and thickening of the frontal and occipital bones reported in some cases.

Differential diagnosis

Erlenmeyer flask deformity is also a prominent feature of the autosomal dominant Braun-Tinschert type of metaphyseal dysplasia (see this term). The two conditions can be distinguished by the mode of inheritance and by the presence of marked varus deformity of the distal part of the radii in Braun-Tinschert metaphyseal dysplasia.

Genetic counseling

Transmission is autosomal recessive.