Acromesomelic dysplasia-2A (AMD2A), or Grebe chondrodysplasia, is an autosomal recessive disorder characterized by severe abnormality of the limbs and limb joints. The severity of limb shortening progresses in a proximal-distal gradient, with the hands and feet being most affected. The fingers and toes lack articulation and appear as skin appendages. In contrast, axial skeletal structures and the craniofacial skeleton are not affected. Heterozygous individuals are of average stature and have mild skeletal abnormalities (summary by Thomas et al., 1997). Because Grebe syndrome exhibits increasing severity in a proximal-distal gradient, it is classified as a form of acromesomelic dysplasia (Costa et al., 1998). For discussion of the genetic heterogeneity of acromesomelic dysplasia, see AMD1 (602875).