Cleidocranial Dysplasia is a hereditary (see: genetic) disorder with over 500² cases reported worldwide. One source³ reports incidence to be 1/2,000,000 persons. In general, Cleidocranial Dysplasia (also known as CCD or Cleidocranial Dysostosis) is characterized by problems surrounding the clavicles, teeth, and pubic bones.
Specifically, common symptoms will include wide fontanels which also tend to close belatedly (ex.1). Symptoms will also include missing or otherwise affected clavicles (collarbone) which allows a number of those affected by the disease to bring their shoulders together completely (ex.2), and the same may occur with the pubic bone¹. Narrow pelvis and chest are also common, the latter of which may cause respiratory difficulties. The joints (acetabula) where the femur connect to the hip-bone may also be prone to dislocation, and spina bifida occulta occurs frequently in the spine (upper thoracic and lower cervical) and sacro (sacroiliac) joints.
Numerous other symptoms occur, including a larger-than-normal head, and others¹. Regarding the dental symptoms and issues, there is generally absent or delayed eruption of teeth through the gums of both permanent and deciduous teeth. Teeth may be abnormally shaped or angled, and patients may experience other dental problems throughout their life. In summary, there are a very wide variety of skeletal-related problems that ensue as a result of this disorder, and it most commonly affects the head, shoulders, pelvis, and teeth, though there may be conditions of the disorder that affect other parts of the body.
Most of these symptoms are not readily visible to most onlookers, really, with the exception of the ability in some to bring their shoulders together completely, and the facial features which generally range from non-existent to moderate. There are various support groups in existence on the Internet for those with the disorder, who may be able to answer further questions; although, in general, there is very little information in general to be had regarding the disorder besides various medical resources. It is, as mentioned before, a rare disease, and in my own research, only a small portion of medical reference books even make reference to the disorder.
It is not rare enough, though, for physicians not to recognize it. My daughter's doctor had been practicing for only a number of years, and he was able to recognize and diagnose it, as well as in myself. It is, as mentioned before, a hereditary disease, and is dominant autosomal; both male and female can carry it or pass it.
This is not exhaustive research. There are many more symptoms that may occur; though each seems to affect the skeletal system, with secondary effects from that. (i.e. respiratory problems from constricted rib-cages) The one book I own on the subject contains a little over a page of text along with numerous X-Ray photographs of affected subjects. This book is McKusick's Heritable Disorders of Connective Tissue, Fifth Edition edited by Peter Beighton, published in 1993 by Mosby-Year Book, Inc. of Missouri. It is possible that other editions of this book are in print, and that other more recent books may exist.
Examples:
1. An extended
soft-spot in children, which will persist for an abnormally long amount of time. Other children will exhibit indentations in their skulls, which may return to normal dependant on how old the child is when such an indentation exists. I myself have a heart-shaped indentation on the left-center side of my skull, approximately three-quarters of a centimeter deep, which I've had since childhood. I am now 20 years of age, and my skull has hardened over completely, which makes the indentation permanent. In general, I don't think I've experienced any side-effects as a result of this. My intelligence is normal, and I do not suffer migraines, or other regular headaches. X-Rays performed in the past have shown nothing except for the fact that my skull is impacted. In addition, my own daughter's soft-spot was, indeed, soft for an unnaturally long time, which simply meant us taking more care to not let her get too many bumps!
2. The only personal experience I have with this is that my daughter's collarbone was broken during the birthing process, though this was not discovered until a number of days after she was born. It was this that led my daughter's doctor to discover that she had the disease, and myself in turn. Her collarbone naturally fused together within months, and has not since had any problems. Recent X-Rays show that there are no obvious problems with her collarbone, which is otherwise intact. My own have not experienced any problems.
Sources:
{1} Beighton, Peter. McKusick's Heritable Disorders of Connective Tissue, Fifth Edition. Mosby-Year Book, Inc., 645-646, 1993.
{2} Cleidocrenial Dysostosis, http://www.icondata.com/health/pedbase/files/CLEIDOCR.HTM, 2003.
{3} Cleidocranial Dysplasia Studies, http://www.themrswebdirectory.com/studies2, February 2001.
{4} W.B. Saunders, http://www.mercksource.com/pp/us/cns/cns_hl_dorlands.jspzQzpgzEzzSzppdocszSzuszSzc ommonzSzdorlandszSzdorlandzSzdmd_d_33zPzhtm, 2002.
{5} Cleidocranial Dysplasia; CCD, http://www3.ncbi.nlm.nih.gov/htbin-post/Omim/dispmim?119600, 2001.