<prompt> Phocomelia:Failure of calcification of cartilageFailure of membranous ossificationFailure of development of flat bonesFailure of development of long bones  <response>: D i.e. Failure of development of long bonesRef: Nelson, 20th editionExplanation:Phocomelia Syndrome PSRare birth defect that causes severe birth defects, especially of the upper limbs.The bones of the arms may be extremely shortened and even absent. The fingers of the hands may be fused.Risk factors:Maternal thalidomide therapy,Genetic inheritance,Roberts syndrome.An extreme case results in the absence of the upper bones of both the arms and legs so that the hands and feet appear attached directly to the body. This is called tetraphocomelia.Other associated anomalies:Encephalocele.Hydrocephalus,Bicornuate uterus.Short neck,Thrombocytopenia,Renal and cardiac anomalies. 