HEREDITARY DEFORMING CHONDRODYSPLASIA 



ALBERT EHRENFRIED 



Boston, Massachusetts 



There is a group of diseases and growth distortions involving the bony- 

 skeleton during its period of development, concerning which knowledge is 

 limited, but in regard to which interest is increasing. These affections have 

 a common bond in that they make their appearance in infancy or childhood 

 and tend to become fixed at skeletal maturity, that they depend upon some 

 inherent disorder of bone formation which evidences itself in skeletal ab- 

 normalities and deformities, and that they can be traced through family 

 lines. 



This group offers a fascinating field for scientific research because it pre- 

 sents clearly that most illusive element in etiology, namely inheritance, and 

 it ties up pathology with biology and genetics in an intriguing fashion. This 

 is properly the field of the physician, because he has the contacts which en- 

 able him to observe and record these cases, even if medicine as yet offers 

 little relief and no solution. On the whole slight attention is paid to these 

 obscure conditions; the study of heredity and genetics in general is given 

 limited space in medical curricula, and abnormalities of this sort are fre- 

 quently dismissed as curiosities, with little effort to solve the mystery of 

 their origin. And yet the only "cure" that medicine can offer is the eugenic 

 prescription of selective mating. 



A serious hindrance to a proper understanding of disorders of this class 

 is the hopeless tangle of medical terminology which surrounds them. And 

 the very designations used in describing these conditions are often confused, 

 — the distinctions between such commonly used terms as "congenital," 

 "inherited," and "familial" are not sharply drawn. 



What is needed is a strict definition of terms, a standard descriptive no- 

 menclature, and a classification which allows each affection to be placed in 

 its proper relation to other members of the group. For instance, properly 

 speaking a disorder is "congenital" only when it is apparent at birth. A 

 disorder may be called "innate" or "inherent" when.it can be referred to 

 some anomaly or peculiarity of the germ plasm. A disorder is "familial" 

 when it occurs in families. A disorder is '^hereditary" only if: 



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