20 Letters to editor

Surgery, Oral Medicine and Oral Pathology. The article contains a serious error which I think should be noted. The authors state that the &year-old son of the proband is to be considered affected with the condition since he has a slightly larger than normal mandible and a nominally deficient maxilla. I would find it difficult to make such a diagnosis on this boy, since he has no supernumerary teeth and no mention is made of abnormalities in his clavicles. One would be hard pressed to consider this child affected solely on the basis of his cephalometric analysis.

My comments are not merely of academic interest but bear extreme importance in the genetic counseling which is given to this boy. If one assumes that this child is affected with the condition, he must be counseled that each of his children will have a 50 percent chance of inheriting the disorder. However, if one determines that he does not have the disorder, then he has essentially a risk no greater than that found in the general population of having a child with the same condition.

I hope that this information will be brought to the attention of the authors. Thank you very much.

Sincerely, L. Stefan Levin, D.D.S., M.S.D.

Assistant Professor Department of Otolaryngology

The Johns Hopkins Hospital Baltimore, Md . 2 1205

To the Editor:

I have several comments to make about a recently published article in the JOURNAL

(Harris et al. 44:830-836, 1977). My first comment concerns nomenclature. Cleidocranial dysplasia (CCD) is the pre-

ferred term for the syndrome purportedly being reviewed by the authors, not cleidocranial dysostosis.

I have three comments on the genetics of CCD. First, the authors’ statement that the “origin” of CCD is unknown is imprecise. CCD is thought to be caused by an autosomal dominant mutant gene. Indeed, the authors mention this in the text. Second, since CCD is clearly a genetic entity, it is difficult to interpret the author’s statement that CCD is “usually hereditary.” This may mean and properly does mean that there may be sporadic cases of CCD due to spontaneous mutation. However, many readers may improperly interpret the phrase “usually hereditary” to imply that some cases may be environmental in origin. Third, the statement that the “trait [appeared] at random in both sexes” can hardly be used to explain the apparently equal sex distribution in past generations. A mutant gene segregates in a very definite way, albeit at random with respect to segregation of the paternal sex chromosomes.

I have four comments on clinical features. First, the clavicular changes in CCD are not pathognomonic as stated. In many cases CCD can be confidently diagnosed without clavicular hypoplasia, and conditions other than CCD may have clavicular hypoplasia. Second, a high, vaulted palate is not a feature of CCD any more than it is of the Down syndrome (another syndrome in which it is reported on the basis of subjective and incom- plete evaluation). Third, the primary indication for removal of the impacted teeth in CCD

Volume 46 Number I Letters to editor 29

is the predictable cystic degeneration around them, not to prevent prosthetic complica- tions. Fourth, CCD does not appear on one or the other side of the body as a variation in its expression; therefore, the diagnoses of CCD in the son and sister of the proband are doubtful. In fact, the only documented evidence of CCD in the family is discontinuity of the clavicles in the proband. (The presence of supernumerary teeth apparently was based on historic account only.)

My final comment concerns Diagram 1. By convention, the use of two or more arrows in a properly strutted pedigree indicates that the identified cases in the family were

ascertained simultaneously. The son in this report was not ascertained at the same time as his father, by the authors’ own account, and the pedigree is misleading.

I hope you and the authors will view my comments as constructive criticism. They are meant to be and, as such, I hope they will help you to maintain the high quality of articles published in the JOURNAL.

Sincerely, Ronald J. Jorgenson, D.D.S.

Associate Professor Department of Oral Medicine

College of Dental Medicine Medical University of South Carolina

80 Barre St. Charleston, S. D. 29401

To the Editor:

In response to the recent letter from Dr. L. Stefan Levin, concerning the case of cleidocranial dysostosis in a father and son, the diagnosis in the son was not made solely on the grounds of cephalometric analysis. Radiologic survey of the son’s clavicles, cervi- cal spine, and other pertinent bones was made. Photographs of the clavicle films were originally included in the article but were withdrawn upon editorial advice. Apparently, the text was also inadvertently omitted. I have enclosed the original photographs of the radiographs, which clearly demonstrate a unilateral deformity consistent with the diag- nosis. The parents were counseled on the possibilities of the son’s offspring being af- fected. Unfortunately, the entire family has not responded to attempts at follow-up.

Thank you very much for your attention to this matter.

Sincerely, Roger J. Harris, D.D.S.

Mystic Medical Arts Building Cow Hill Road

Mystic, Conn. 06355