page_title: Bonnet–Dechaume–Blanc syndrome
section_title: Causes
hierarchical_section_title: Bonnet–Dechaume–Blanc syndrome / Causes
caption_attribution_description: Black and white image of the retina during the effects of w:Fluorescein_angiography. (The ink of the image has smeared in the bottom right corner)
context_page_description: Bonnet–Dechaume–Blanc syndrome, also known as Wyburn-Mason syndrome, is a rare congenital disorder characterized by arteriovenous malformations of the brain, retina or facial nevi. The syndrome has a number of possible symptoms and can, more rarely, affect the skin, bones, kidneys, muscles, and gastrointestinal tract. When the syndrome affects the brain, people can experience severe headaches, seizures, acute stroke, meningism, and progressive neurological deficits due to acute or chronic ischaemia caused by arteriovenous shunting.
  In the retina, the syndrome causes retinocephalic vascular malformations that tend to be present with intracranial hemorrhage and lead to decreased visual acuity, proptosis, pupillary defects, optic atrophy, congestion of bulbar conjunctiva, and visual field defects. Retinal lesions can be unilateral and tortuous, and symptoms begin to appear in the second and third decades of life.
  The syndrome can present with cutaneous lesions, or skin with different texture, thickness, and color, usually on the face. The facial features caused by the syndrome vary from slight discoloration to extensive nevi and angiomas of the skin.
context_section_description: Bonnet–Dechaume–Blanc syndrome results from arteriovenous malformations. The exact cause of this disorder is unknown, and no specific genetic abnormality has been identified. The syndrome is a congenital disorder that begins to develop around the seventh week of gestation when the maturation of retinal mesenchymal cells do not grow properly. The abnormal development of vascular tissue leads to arteriovenous malformations, which affect both visual and cerebral structures.
caption: Fluorescein angiography can reveal arteriovenous malformations.
exif: {"Image Orientation": "Horizontal (normal)", "Image XResolution": "96", "Image YResolution": "96", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "Adobe Photoshop CS2 Windows", "Image DateTime": "2009:12:07 18:49:18", "Image ExifOffset": "164", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "302", "Thumbnail JPEGInterchangeFormatLength": "3652", "EXIF ColorSpace": "Uncalibrated", "EXIF ExifImageWidth": "736", "EXIF ExifImageLength": "600"}