Information on the following diseases can be found in the Related Disorders section of this report:

• Chondrodysplasia Punctata, Rhizomelic Type
• Fetal Warfarin Syndrome
• Associated Disorders (General)
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In most affected individuals, Binder type maxillonasal dysplasia is primarily characterized by malformation of the nasal and upper jaw (nasomaxillary) regions. The maxillae are the large bones that form the upper jaw and assist in the formation of the nasal cavities, the bony cavities containing the eyeballs (orbits), and the roof of the mouth (palate). The maxillae also contain the sockets of the upper teeth.

In those with Binder type maxillonasal dysplasia, characteristic facial abnormalities may include a small, short nose; flattening of the nasal tip and the "wings" forming the outer side of each nostril (alae); and flattening or depression of the nasal bridge. The condition is also typically characterized by shortness of the fleshy margin (columella) of the nasal septum, which is the central partition separating the two nasal cavities. (The nasal septum is composed of cartilage and bone and covered by mucous membrane [nasal mucosa].) In addition, when viewed from below, the nostrils have a distinctive "half-moon" or "cat's-ear" shape. Although there is also reduction of the nasal mucosa, affected individuals typically have a normal sense of smell.

Binder type maxillonasal dysplasia is also commonly associated with malocclusion, a dental condition in which teeth of the upper jaw are improperly positioned in relation to those of the lower jaw (mandible). More specifically, affected individuals may be predisposed to class III malocclusion, in which the mandible is too far forward, the cusps of the lower back teeth are abnormally positioned in front of corresponding upper (maxillary) back teeth, and the lower front teeth (incisors) meet or lie in front of the maxillary incisors.

Additional facial abnormalities are also often associated with Binder type maxillonasal dysplasia. The upper lip typically has an unusually convex or outwardly curved contour. Associated features also commonly include flattening of the maxillary base; poor development of the vertical groove in the center of the upper lip (philtrum); and/or absence or underdevelopment of certain air-filled spaces of the skull that open into the nasal cavities (frontal sinuses).

In some cases, additional symptoms and physical findings have been reported in association with the condition, such as hearing impairment; frequent upper respiratory tract infections; various malformations of the spinal column of the neck (cervical vertebral defects); abnormal sideways or front-to-back curvature of the spine; and/or other skeletal abnormalities. Less commonly, additional reported features have included incomplete closure of the roof of the mouth (cleft palate); an abnormal groove in the upper lip (cleft lip); misalignment of the eyes (strabismus); various structural malformations of the heart (congenital heart defects); mild mental retardation; and/or other features.
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In most cases, Binder type maxillonasal dysplasia appears to occur randomly for unknown reasons (sporadically). A few familial cases have also been described in which siblings or a parent and child have been affected. Some researchers suggest that familial cases may represent autosomal dominant or autosomal recessive inheritance with reduced penetrance.

Human traits, including the classic genetic diseases, are the product of the interaction of two genes, one received from the father and one from the mother. In autosomal dominant disorders, a single copy of the disease gene (received from either the mother or father) may be expressed "dominating" the other normal gene and resulting in the appearance of the disease. The risk of transmitting the disease gene from affected parent to offspring is 50 percent for each pregnancy regardless of the sex of the resulting child.

In autosomal recessive disorders, the condition does not appear unless a person inherits the same defective gene for the same trait from each parent. If an individual receives one normal gene and one gene for the disease, the person will be a carrier for the disease but usually will not show symptoms. The risk of transmitting both disease genes to the children of a couple, both of whom are carriers for a recessive disorder, is 25 percent. Fifty percent of their children risk being carriers of the disease but generally will not show symptoms of the disorder. Twenty-five percent of their children may receive both normal genes, one from each parent, and will be genetically normal (for that particular trait). The risk is the same for each pregnancy.

Reduced penetrance indicates that fewer than 100 percent of those with the defective gene(s) for the disorder exhibit associated symptoms and findings.

Although some investigators suggest that familial Binder type maxillonasal dysplasia may be transmitted as an autosomal dominant or autosomal recessive trait, others indicate that it probably does not result from "monogenic" transmission. Rather, they indicate that the condition may be caused by various complex genetic factors or "multifactorial" inheritance. Monogenic transmission is the acquisition of a particular trait, the transmission of which depends on a single gene, while multifactorial inheritance is determined by multiple genetic and, possibly, environmental factors.

As mentioned previously, many researchers indicate that Binder type maxillonasal dysplasia probably does not represent a distinct disease entity. Instead, they suggest that it may be a nonspecific abnormality of the nasomaxillary regions that may occur as an isolated condition or in association with various underlying syndromes. In addition, some investigators have noted that the condition should be classified as a mild form of chondrodysplasia punctata, rhizomelic type. Reports also indicate that some individuals diagnosed with Binder type maxillonasal dysplasia have had a maternal history of warfarin therapy during pregnancy. (For further information, please see the "Related Disorders" section of this report below.)
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Binder type maxillonasal dysplasia is a rare condition that appears to affect males and females in relatively equal numbers. Since the condition was described in the medical literature in 1962, more than 100 cases have been reported. Binder type maxillonasal dysplasia is detectable at birth but, in some cases, may not be diagnosed until years later.
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Symptoms of the following disorders may be similar to those of Binder type maxillonasal dysplasia. Comparisons may be useful for a differential diagnosis:

Chondrodysplasia punctata, rhizomelic type (CDPR), is a rare, multisystem disorder that has been shown to be associated with impaired peroxisomal functioning. Peroxisomes are tiny, specialized structures (organelles) within cells that play an essential role in various, ongoing chemical and physical processes in the body (metabolism). CDPR is characterized by the appearance of abnormal, dotlike opacities representing an accumulation of calcium salts (calcification) within the growing ends of certain long bones (i.e., stippled epiphyses); shortening of the long bones of the upper arms (humeri) and the thigh bones (femora); and short stature. The disorder is also typically associated with irregularities of certain bones of the spinal column (vertebrae) and fixed bending or extension of multiple joints (contractures). Affected individuals may also have facial abnormalities that resemble those associated with Binder type maxillonasal dysplasia, such as a flattened midface (midfacial hypoplasia), with underdevelopment of the nose (nasal hypoplasia), a low nasal bridge, and small nostrils. Additional abnormalities may include an unusually small head (microcephaly); upwardly slanting eyelid folds (palpebral fissures); loss of transparency of the lenses of the eyes (cataracts); abnormal thickening, dryness, and scaling of the skin (ichthyosis); and/or severe mental retardation. CDPR is inherited as an autosomal recessive trait.

As mentioned above, some researchers suggest that Binder type maxillonasal dysplasia should be classified as a mild form of CDPR. According to such investigators, many individuals with Binder type maxillonasal dysplasia seek medical attention during adolescence; however, by that time, certain diagnostic x-ray features of CDPR are no longer present. Thus, in such cases, CDPR often may not be considered as a diagnosis.

Fetal warfarin syndrome refers to a characteristic pattern of birth defects in a newborn resulting from exposure to certain anticlotting drugs (coumarin group), such as warfarin, during pregnancy. Evidence suggests that the greatest period of risk occurs from approximately six to nine weeks following conception. The most consistent feature is midfacial hypoplasia, with an unusually small, flattened nose; a deep groove between the "wings" of the nose (alae) and the tip; and abnormally small nostrils. Additional abnormalities may include growth deficiency before birth; mental retardation; an abnormally small head (microcephaly); hearing loss; sudden episodes of uncontrolled electrical activity in the brain (seizures); cataracts; abnormal clouding of the normally transparent regions forming the front of the eyeballs (corneal opacities); and/or other features.

As noted previously, some individuals diagnosed with Binder type maxillonasal dysplasia have had a maternal history of warfarin therapy during pregnancy. In addition, maternal use of certain anticlotting agents in early pregnancy may result in features resembling CDPR, including nasal hypoplasia, abnormal accumulation of calcium salts (calcification) within the growing ends of certain long bones (stippled epiphyses), disproportionate short stature, and/or other abnormalities.

Additional disorders may also be characterized by certain symptoms and findings that resemble those associated with Binder type maxillonasal dysplasia. (For further information, choose the exact disease name in question as your search term in the Rare Disease Database.)

Diagnosis
Reports indicate that, in some cases, a diagnosis of Binder type maxillonasal dysplasia may be suggested before birth (prenatally) by ultrasound. During fetal ultrasonography, reflected sound waves create an image of the developing fetus.

Binder type maxillonasal dysplasia may be diagnosed or confirmed at birth. However, as noted above, the condition may sometimes not be recognized until adolescence or later. The diagnosis may be made based upon a complete patient and family history, a thorough clinical evaluation, and specialized tests, including imaging techniques. X-ray findings may include underdevelopment (hypoplasia) or absence of a bony projection of the upper jaw (i.e., anterior nasal spine) that joins with bone of the nasal septum; thinness of a portion of the upper jaw (known as alveolar bone) that forms the dental arch over the upper incisors; hypoplasia or absence of frontal sinuses; and/or certain abnormalities detected with cephalometric studies, which are scientific measurements of particular craniofacial dimensions.

Treatment
The treatment of Binder type maxillonasal dysplasia may require the coordinated efforts of a team of medical professionals, such as pediatricians or internists; specialists in the diagnosis, prevention, and correction of malocclusion (orthodontists); oral and plastic surgeons; physicians who diagnose and treat disorders of the skeleton, muscles, joints, and related tissues (orthopedists); and/or other health care professionals.

Recommended treatment may include various orthodontic and surgical measures to help correct abnormalities of the jaw and nose, such as the use of orthodontic devices, surgery to reposition the jaw (orthognathic surgery), measures to expand tissues of the midface, bone grafts or implants, and/or other methods. In some cases, physicians may also recommend surgical or other measures to help treat additional abnormalities that may be associated with the condition. In individuals with Binder type maxillonasal dysplasia, specific surgical procedures performed will depend on the nature, severity, and/or combination of anatomical abnormalities, patient age, and other factors.

Genetic counseling may be of benefit for affected individuals and their families. Other treatment for this condition is symptomatic and supportive.

Research on birth defects and their causes is ongoing. The National Institutes of Health (NIH) is sponsoring the Human Genome Project which is aimed at mapping every gene in the human body and learning why they sometimes malfunction. It is hoped that this new knowledge will lead to prevention and treatment of genetic disorders in the future.

Online Mendelian Inheritance in Man, OMIM (TM). John Hopkins University, Baltimore, MD. MIM Number 155050; 5/3/99. Available at: http://www.ncbi.nlm.nih.gov/htbin-post/Omim/dispmim?155050.

Online Mendelian Inheritance in Man, OMIM (TM). John Hopkins University, Baltimore, MD. MIM Number 215100; 2/27/01. Available at: http://www.ncbi.nlm.nih.gov/htbin-post/Omim/dispmim?215100.

TEXTBOOKS
Gorlin RJ, et al., eds. Syndromes of the Head and Neck. 3rd ed. New York, NY: Oxford University Press; 1990:22, 190-92, 813-14.

Buyse ML. Birth Defects Encyclopedia. Dover, Mass: Blackwell Scientific Publications, Inc; 1990:731-32, 1110-11.

JOURNAL ARTICLES
Cook K, et al. The prenatal diagnosis of Binder syndrome before 24 weeks of gestation: case report. Ultrasound Obstet Gynecol. 2000;16:578-81.

Rune B, et al. Bone grafts to the nose in Binder's syndrome (maxillonasal dysplasia): a follow-up of eleven patients with the use of profile roentgenograms. Plast Reconstr Surg. 1998;101:297-304; discussion 305-06.

Tripi TR. Report of a case of maxillo-nasal dysplasia (Binder syndrome). Minerva Stomatol. 1997;46:609-14.

Monasterio FO, et al. Nasal correction in Binder's syndrome: the evolution of a treatment plan. Aesthetic Plast Surg. 1997;21:299-308.

Roy-Doray B, et al. Binder syndrome in a mother and her son. Genet Couns. 1997;8:227-33.

Quarrell OWJ, et al. Maxillonasal dysplasia (Binder's syndrome). J Med Genet. 1990;27:384-87.

Olow-Nordenram M, et al. The craniofacial morphology in persons with maxillonasal dysplasia (Binder syndrome). A longitudinal cephalometric study of orthodontically treated children. Am J Orthod Dentofacial Orthop. 1989;95:148-58.

Olow-Nordenram M, et al. An etiologic study of maxillo-nasal dysplasia: Binder's syndrome. Scand J Dent Res. 1988;96:69-74.

Olow-Nordenram M. Maxillonasal dysplasia (Binder's syndrome). A study of craniofacial morphology, associated malformations and familial relations. Swed Dent J Suppl. 1987;47:1-38.

Horswell BB, et al. Maxillonasal dysplasia (Binder's syndrome): a critical review and case study. J Oral Maxillofac Surg. 1987;45:114-22.

Gross-Kieselstein E, et al. Familial variant of maxillonasal dysplasia? J Craniofac Genet Dev Biol. 1986;6:331-34.

Harrod MJE, et al. Warfarin embryopathy in siblings. Obstet Gynec. 1981;57:673-76.