Mondo Description Achondrogenesis type 1B (ACG1B), a form of achondrogenesis, is a rare lethal skeletal dysplasia characterized by severe micromelia with very short fingers and toes, a flat face, a short neck, thickened soft tissue around the neck, hypoplasia of the thorax, protuberant abdomen, a hydropic fetal appearance and distinctive histological features of the cartilage.

Uniprot Description A form of achondrogenesis type 1, a lethal form of chondrodysplasia characterized by deficient ossification in the lumbar vertebrae and absent ossification in the sacral, pubic and ischial bones and clinically by stillbirth or early death. In addition to severe micromelia, there is a disproportionately large cranium due to marked edema of soft tissues. ACG1B is an autosomal recessive disease.