Pyknoachondrogenesis
Pyknoachondrogenesis is a very rare, fatal, presumably autosomal recessive genetic disorder characterized by symptoms similar to those shown by patients with achondrogenesis alongside severely osteoclerotic bones and early death. The findings that can be seen in patients with this condition include hydrops fetalis, palpebral edemas, low-set ears, abdomen prominence, short neck, large head, depressed nasal bridge, shortening and widening of the trunk, severe short-limbed dwarfism, craniofacial hyperostosis, agenesis of the pubic bones, hypoplasia of the pelvic bones and ischium, poor ossification of the vertebrae and sacrum, webbing of the neck, and shortening of a long bone and the ribs. Pregnancies of babies with this condition generally aren't compatible with life and they end up in miscarriage, stillbirth, or in neonatal death. Only 5 cases from Italy and the United States, respectively, have been described in medical literature.