Última actualización:
October 04, 2012
Años publicados: 1992, 2000, 2009, 2012
NORD gratefully acknowledges James Reynolds, MD, FAAP, FACMG, Medical Geneticist, Shodair Children’s Hospital, for assistance in the preparation of this report.
Maxillofacial dysostosis is an extremely rare genetic disorder characterized by distinctive abnormalities of the head and face (craniofacial) area. Major symptoms include an underdeveloped (hypoplasia) upper jaw, downward-slanting palpebral fissures (which means that the opening between the eyelids slants downward), minor malformations of the external portion of the ears, and speech abnormalities. Maxillofacial dysostosis is inherited as an autosomal dominant trait. A second (distinct) form of maxillofacial dysostosis is believed to be inherited as an X-linked recessive trait.
The symptoms and physical findings associated with maxillofacial dysostosis may vary from one person to another. Because so few cases have been identified and reported, it will be difficult to obtain an accurate clinical picture of the disorder. Affected individuals or parents of affected children should talk to their physicians and medical team about their specific case and associated symptoms.
Characteristic findings associated with maxillofacial dysostosis include an underdeveloped (hypoplastic) upper jaw (maxilla), an abnormal downward slant of the opening between the eyelids (palpebral fissures), minor external ear malformations and speech abnormalities.
Although most individuals with maxillofacial dysostosis have normal intelligence, they are often mistakenly thought to be mentally challenged due to their language problems. Their progress should be carefully monitored and educators should be informed of the potential for delayed onset of speech and difficulties with speech development including poor speech articulation (dysarthria).
External ear abnormalities may include malformation of the upper, outer portion of the ear (pinna or auricle). Hearing loss was not seen in any of the individuals with maxillofacial dysostosis reported in the medical literature. Additional symptoms that have been reported in some cases of maxillofacial dysostosis include a sunken chest (pectus excavatum), incomplete or underdeveloped nipples, an abnormally flat skull, and a flattened bridge of the nose. Certain eye abnormalities including drooping of the upper eyelid (ptosis), crossed eyes (strabismus), and rapid, involuntary movements of the eyes (nystagmus) have also been reported.
Maxillofacial dysostosis is inherited as an autosomal dominant trait. Genetic diseases are determined by the combination of genes for a particular trait that are on the chromosomes received from the father and the mother. Dominant genetic disorders occur when only a single copy of an abnormal gene is necessary for the appearance of the disease. The abnormal gene can be inherited from either parent, or can be the result of a new mutation (gene change) in the affected individual. The risk of passing the abnormal gene from affected parent to offspring is 50 percent for each pregnancy regardless of the sex of the resulting child.
Maxillofacial dysostosis is extremely rare and the exact incidence of the disorder is unknown. Approximately 12 cases have been reported in the medical literature. Researchers believe that cases of maxillofacial dysostosis may go misdiagnosed or unrecognized making it difficult to determine the true frequency of the disorder in the general population. Maxillofacial dysostosis most likely affects males and females in equal numbers.
A diagnosis of maxillofacial dysostosis is made based upon identification of characteristic symptoms, a detailed patient history, a thorough clinical evaluation and a variety of specialized tests to rule out other disorders.
Treatment
The treatment of maxillofacial dysostosis is directed toward the specific symptoms that are apparent in each individual. Facial features may improve with age, often resulting in a near normal appearance by adulthood. When facial abnormalities are severe a variety of medical techniques including plastic surgery or orthodontic repair may be necessary.
Genetic counseling may be of benefit for affected individuals and their families. Other treatment is symptomatic and supportive.
Information on current clinical trials is posted on the Internet at www.clinicaltrials.gov. All studies receiving U.S. Government funding, and some supported by private industry, are posted on this government web site.
For information about clinical trials being conducted at the NIH Clinical Center in Bethesda, MD, contact the NIH Patient Recruitment Office:
Tollfree: (800) 411-1222
TTY: (866) 411-1010
Email: prpl@cc.nih.gov
For information about clinical trials sponsored by private sources, contact:
www.centerwatch.com
For information about clinical trials sponsored by private sources, contact:
www.centerwatch.com
Contact for additional information about maxillofacial dysostosis:
James Reynolds, MD, FAAP, FACMG
Medical Geneticist
Shodair Children’s Hospital
2755 Colonial Drive
Helena, MT 59601
Phone: 800-447-6614
Email: JReynolds@shodair.org
TEXTBOOKS
Gorlin RJ, Cohen MM Jr, Hennekam RCM. Eds. Syndromes of the Head and Neck. 4th ed. New York, NY: Oxford University Press; 2001:809.
Buyse ML, ed. Birth Defects Encyclopedia. Dover, MA: Blackwell Scientific Publications; For: The Center for Birth Defects Information Services Inc; 1990:1109.
JOURNAL ARTICLES
Ensink RJH, Brunner HG, Cremers CWRJ. A new type of maxillofacial dysostosis, inherited as an x-linked recessive trait. Gen Couns. 1997;8:285-290.
Escobar V, Eastman J, Weaver D, Melnick M. Maxillofacial dysostosis. J Med Genet. 1977;14:355-358.
Melnick M, Eastman JR. Autosomal dominant maxillofacial dysostosis. Birth Defects Orig Art Ser. 1977;XIII(3B):39-44.
INTERNET.
Online Mendelian Inheritance in Man (OMIM). The Johns Hopkins University. Maxillofacial Dysostosis. Entry No: 155000. Last Edited March 18, 2004. Available at: https://www.ncbi.nlm.nih.gov/omim/. Accessed October 4, 2012.
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