Spondyloepiphyseal dysplasia (SED) is a descriptive term for a group of disorders with primary involvement of the vertebrae and epiphyseal centers resulting in a short-trunk disproportionate dwarfism. SED, metatropic dysplasia, and Kniest syndrome are considered short-trunk dwarfing conditions. 

Two major types of SED are recognized

1. SED congenita

2. SED tarda

SED congenita is a nonlethal form of congenital dwarfism characterized by typical skeletal dysplasias, vertebral changes, and ocular manifestations. It can be diagnosed at birth. In contrast, SED tarda is milder than SED congenita, late in onset, and appearance may be normal at birth. 

SED congenita is autosomal dominant; hence, males and females are affected in equal numbers. SED tarda is X-linked recessive; hence, only males are affected. 

Radiographic findings: