Chondrodysplastic Dwarfism Research Articles

A skeletal growth defect in the puma (Felis concolor)

Clinical and radiological signs shown by a young deformed puma cub, and the pathological findings following its euthanasia at eight months, are presented. These findings do not resemble those in the recognised nutritional bone diseases of the growing carnivore, but closely resemble an hereditary disease of the dog and, at least in one respect, an hereditary disease in man. This case may be an example of hereditary chondrodysplastic dwarfism in the puma. An unusual finding was the presence of iron in the cartilage of abnormal growth plates.

Hereditary Stomatocytosis With Hemolytic Anemia in the Dog

Abstract An autosomal recessive mutant (symbol, dan) in the dog causes chondrodysplastic dwarfism and mild anemia as pleiotropic effects. The anemia is characterized by stomatocytosis, macrocytosis, low MCHC, increased osmotic fragility, shortened red cell survival, reticulocytosis, erythroid hyperplasia, and increased iron turnover. Minor changes can be detected in the red cells of heterozygous carriers of the dan gene, but red cell survival is normal and chondrodysplasia is not present. Red cell sodium concentration and water content are increased in anemic dogs and to a lesser degree in carriers. Glutathione deficiency is present. The disorder described here resembles a number of human hemolytic anemias with stomatocytosis, glutathione deficiency, and disordered red cell cation and water content, and further study of the dan mutant, together with investigations of the hereditary human conditions, will elucidate the maintenance of normal red cell cation balance.

Lethal Forms of Chondrodysplastic Dwarfism

Thanatophoric dwarfism and achondrogenesis are lethal forms of skeletal dysplasia with clinical, radiographic, and genetic features distinct from classic achondroplasia. Both of these forms of lethal chondrodystrophy continue to be mistaken for achondroplasia, with serious genetic implications, since present evidence suggests that at least achondrogenesis is the result of autosomal recessive inheritance. This report presents the clinical, radiographic, and autopsy findings in three short-limbed infants who died soon after birth. Early death is due to respiratory insufficiency secondary to severe pulmonary hypoplasia and, in one case, dysplasia of the tracheal rings. The incidence of lethal chondrodystrophies is about one in 19,000 live births. It is suggested that the differential diagnosis between thanatophoric dwarfism and achondrogenesis can be established unequivocally on radiographic grounds, as can the differentiation of these two lethal skeletal dysplasias from classic achondroplasia. It is important for proper genetic counseling that these distinctions be made.