In cases of sporadic achondroplasia as well as in fibrodysplasia ossificans progressiva, there is a strong association with paternal age,

Adv Exp Med Biol. 2010;686:335-48.

Osteochondral diseases and fibrodysplasia ossificans progressiva.
Morales-Piga A, Kaplan FS.

Jefe de Servicio de Proyectos Clínicos del Instituto de Investigación de Enfermedades Raras, Instituto de Salud Carlos III, Sinesio Delgado, 6, 28029, Madrid, Spain, amorales@isciii.es.

Abstract
Osteochondrodysplasias like thanatophoric dysplasia, osteogenesis imperfecta, achondroplasia, and other genetic skeletal disorders like fibrodysplasia ossificans progressiva are infrequently seen in clinical practice. In cases of sporadic achondroplasia as well as in fibrodysplasia ossificans progressiva, there is a strong association with paternal age, a relationship that is less evident in other genetic osteochondral diseases. No other constitutional or environmental factor has proven to be associated with these disorders. The use of prenatal ultrasonography as a routine component of prenatal care is crucial in the early suspicion of osteochondrodysplasias whereas definitive diagnosis is usually obtained by pre-natal molecular analysis. In the case of fibrodysplasia ossificans progressiva, recognition of congenital great toe malformations associated with rapidly-appearing soft tissue swelling is sufficient to make the proper clinical diagnosis, which can be confirmed by genetic testing. Large regional centres will improve diagnosis performance, provide accurate genetic counselling, and ensure an integral assistance for these often severe and incapacitating conditions.