Achondrogenesis type 1B (ACG1B), a form of achondrogenesis (see this term), 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. The disease is Achondrogenesis type 1B (Orphanet rare-disease nomenclature id Orphanet_93298). Also known as: Achondrogenesis, Parenti-Fraccaro type.