| Definition: |
A spondylometaphyseal dysplasia characterized by postnatal growth deficiency, profound short stature, rhizomelia with bowing of the lower extremities, platyspondyly with anterior vertebral protrusions, progressive metaphyseal irregularity and cupping with shortened tubular bones, and early-onset progressive visual impairment associated with a pigmentary maculopathy and electroretinographic evidence of cone-rod dysfunction that has_material_basis_in homozygous or compound heterozygous mutation in the PCYT1A gene on chromosome 3q29. |