FBN1 Gene

Weill-Marchesani syndrome is a disorder of connective tissue. Connective tissue forms the body's supportive framework, providing structure and strength to the muscles, joints, organs, and skin.

The major signs and symptoms of Weill-Marchesani syndrome include short stature, eye abnormalities, unusually short fingers and toes (brachydactyly), and joint stiffness. Adult height for men with Weill-Marchesani syndrome ranges from 4 feet, 8 inches to 5 feet, 6 inches. Adult height for women with this condition ranges from 4 feet, 3 inches to 5 feet, 2 inches.

An eye abnormality called microspherophakia is characteristic of Weill-Marchesani syndrome. This term refers to a small, sphere-shaped lens, which is associated with nearsightedness (myopia) that worsens over time. The lens also may be positioned abnormally within the eye (ectopia lentis). Many people with Weill-Marchesani syndrome develop glaucoma, an eye disease that increases the pressure in the eye and can lead to blindness.

Occasionally, heart defects or an abnormal heart rhythm can occur in people with Weill-Marchesani syndrome.

Marfan syndrome is a disorder that affects the connective tissue in many parts of the body. Connective tissue provides strength and flexibility to structures such as bones, ligaments, muscles, blood vessels, and heart valves. The signs and symptoms of Marfan syndrome vary widely in severity, timing of onset, and rate of progression.

Because connective tissue is found throughout the body, Marfan syndrome can affect many systems, often causing abnormalities in the heart, blood vessels, eyes, bones, and joints. The two primary features of Marfan syndrome are vision problems caused by a dislocated lens (ectopia lentis) in one or both eyes and defects in the large blood vessel that distributes blood from the heart to the rest of the body (the aorta). The aorta can weaken and stretch, which may lead to a bulge in the blood vessel wall (an aneurysm). Stretching of the aorta may cause the aortic valve to leak, which can lead to a sudden tearing of the layers in the aorta wall (aortic dissection). Aortic aneurysm and dissection can be life threatening.

Many people with Marfan syndrome have additional heart problems including a leak in the valve that connects two of the four chambers of the heart (mitral valve prolapse) or the valve that regulates blood flow from the heart into the aorta (aortic valve regurgitation). Leaks in these valves can cause shortness of breath, fatigue, and an irregular heartbeat felt as skipped or extra beats (palpitations).

Individuals with Marfan syndrome are usually tall and slender, have elongated fingers and toes (arachnodactyly), loose joints, and have an arm span that exceeds their body height. Other common features include a long and narrow face, crowded teeth, an abnormal curvature of the spine (scoliosis or kyphosis), stretch marks (striae) not related to weight gain or loss, and either a sunken chest (pectus excavatum) or a protruding chest (pectus carinatum). Some individuals develop an abnormal accumulation of air in the chest cavity that can result in the collapse of a lung (spontaneous pneumothorax). A membrane called the dura, which surrounds the brain and spinal cord, can be abnormally enlarged (dural ectasia) in people with Marfan syndrome. Dural ectasia can cause pain in the back, abdomen, legs, or head. Most individuals with Marfan syndrome have some degree of nearsightedness (myopia). Clouding of the lens (cataract) may occur in mid-adulthood, and increased pressure within the eye (glaucoma) occurs more frequently in people with Marfan syndrome than in those without the condition.

The features of Marfan syndrome can become apparent anytime between infancy and adulthood. Depending on the onset and severity of signs and symptoms, Marfan syndrome can be fatal early in life; however, with proper treatment, many affected individuals have normal lifespans.

Acromicric dysplasia is a condition characterized by severely short stature, short limbs, stiff joints, and distinctive facial features.

Newborns with acromicric dysplasia are of normal size, but slow growth over time results in short stature. The average height of adults with this disorder is about 4 feet, 2 inches for women and 4 feet, 5 inches for men. The long bones of the arms and legs, and the bones in the hands and feet, are shorter than would be expected for the individual's height. Other skeletal features that occur in this disorder include slowed mineralization of bone (delayed bone age), abnormally shaped bones of the spine (vertebrae), and constrained movement of joints. Affected individuals often develop carpal tunnel syndrome, which is characterized by numbness, tingling, and weakness in the hands and fingers. A misalignment of the hip joints (hip dysplasia) can also occur in this disorder. These skeletal and joint problems may require treatment, but most affected individuals have few limitations in their activities.

Children with acromicric dysplasia may have a round face, sharply defined eyebrows, long eyelashes, a bulbous nose with upturned nostrils, a long space between the nose and upper lip (long philtrum), and a small mouth with thick lips. These facial differences become less apparent in adulthood. Intelligence is unaffected in this disorder, and life expectancy is generally normal.

Isolated ectopia lentis is a condition that affects the eyes, specifically the positioning of the lens. The lens is a clear structure at the front of the eye that helps focus light. In people with isolated ectopia lentis, the lens in one or both eyes is not centrally positioned as it should be but is off-center (displaced). Isolated ectopia lentis usually becomes apparent in childhood. The lens may drift further off-center over time.

Vision problems are common in isolated ectopia lentis. Affected individuals often have nearsightedness (myopia) and can have an irregular curvature of the lens or a structure that covers the front of the eye (the cornea), which causes blurred vision (astigmatism). They may also develop clouding of the lenses (cataracts) or increased pressure in the eyes (glaucoma) at an earlier age than other adults. In a small number of people with isolated ectopia lentis, tearing of the back lining of the eye (retinal detachment) occurs, which can lead to further vision problems and possible blindness.

In individuals with isolated ectopia lentis, each eye can be affected differently. In addition, the eye problems vary among affected individuals, even those within the same family.

Ectopia lentis is classified as isolated when it occurs alone without signs and symptoms affecting other body systems. Ectopia lentis can also be classified as syndromic, when it is part of a syndrome that affects multiple parts of the body. Ectopia lentis is a common feature of genetic syndromes such as Marfan syndrome and Weill-Marchesani syndrome.

Familial thoracic aortic aneurysm and dissection (familial TAAD) involves problems with the aorta, which is the large blood vessel that distributes blood from the heart to the rest of the body. Familial TAAD affects the upper part of the aorta, near the heart. This part of the aorta is called the thoracic aorta because it is located in the chest (thorax). Other vessels that carry blood from the heart to the rest of the body (arteries) can also be affected.

In familial TAAD, the aorta can become weakened and stretched (aortic dilatation), which can lead to a bulge in the blood vessel wall (an aneurysm). Aortic dilatation may also lead to a sudden tearing of the layers in the aorta wall (aortic dissection), allowing blood to flow abnormally between the layers. These aortic abnormalities are potentially life-threatening because they can decrease blood flow to other parts of the body such as the brain or other vital organs, or cause the aorta to break open (rupture).

The occurrence and timing of these aortic abnormalities vary, even within the same affected family. They can begin in childhood or not occur until late in life. Aortic dilatation is generally the first feature of familial TAAD to develop, although in some affected individuals dissection occurs with little or no aortic dilatation.

Aortic aneurysms usually have no symptoms. However, depending on the size, growth rate, and location of these abnormalities, they can cause pain in the jaw, neck, chest, or back; swelling in the arms, neck, or head; difficult or painful swallowing; hoarseness; shortness of breath; wheezing; a chronic cough; or coughing up blood. Aortic dissections usually cause severe, sudden chest or back pain, and may also result in unusually pale skin (pallor), a very faint pulse, numbness or tingling (paresthesias) in one or more limbs, or paralysis.

Familial TAAD may not be associated with other signs and symptoms. However, some individuals in affected families show mild features of related conditions called Marfan syndrome or Loeys-Dietz syndrome. These features include tall stature, stretch marks on the skin, an unusually large range of joint movement (joint hypermobility), and either a sunken or protruding chest. Occasionally, people with familial TAAD develop aneurysms in the brain or in the section of the aorta located in the abdomen (abdominal aorta). Some people with familial TAAD have heart abnormalities that are present from birth (congenital). Affected individuals may also have a soft out-pouching in the lower abdomen (inguinal hernia), an abnormal curvature of the spine (scoliosis), or a purplish skin discoloration (livedo reticularis) caused by abnormalities in the tiny blood vessels of the skin (dermal capillaries). However, these conditions are also common in the general population. Depending on the genetic cause of familial TAAD in particular families, they may have an increased risk of developing blockages in smaller arteries, which can lead to heart attack and stroke.

Geleophysic dysplasia is an inherited condition that affects many parts of the body. It is characterized by abnormalities involving the bones, joints, heart, and skin.

People with geleophysic dysplasia have short stature with very short hands and feet. Most also develop thickened skin and joint deformities called contractures, both of which significantly limit mobility. Affected individuals usually have a limited range of motion in their fingers, toes, wrists, and elbows. Additionally, contractures in the legs and hips cause many affected people to walk on their toes.

The name of this condition, which comes from the Greek words for happy ("gelios") and nature ("physis"), is derived from the good-natured facial appearance seen in most affected individuals. The distinctive facial features associated with this condition include a round face with full cheeks, a small nose with upturned nostrils, a broad nasal bridge, a thin upper lip, upturned corners of the mouth, and a flat area between the upper lip and the nose (philtrum).

Geleophysic dysplasia is also characterized by heart (cardiac) problems, particularly abnormalities of the cardiac valves. These valves normally control the flow of blood through the heart. In people with geleophysic dysplasia, the cardiac valves thicken, which impedes blood flow and increases blood pressure in the heart. Other heart problems have also been reported in people with geleophysic dysplasia; these include a narrowing of the artery from the heart to the lungs (pulmonary stenosis) and a hole between the two upper chambers of the heart (atrial septal defect).

Other features of geleophysic dysplasia can include an enlarged liver (hepatomegaly) and recurrent respiratory and ear infections. In severe cases, a narrowing of the windpipe (tracheal stenosis) can cause serious breathing problems. As a result of heart and respiratory abnormalities, geleophysic dysplasia is often life-threatening in childhood. However, some affected people have lived into adulthood.

Weill-Marchesani syndrome is a disorder of connective tissue. Connective tissue forms the body's supportive framework, providing structure and strength to the muscles, joints, organs, and skin.

The major signs and symptoms of Weill-Marchesani syndrome include short stature, eye abnormalities, unusually short fingers and toes (brachydactyly), and joint stiffness. Adult height for men with Weill-Marchesani syndrome ranges from 4 feet, 8 inches to 5 feet, 6 inches. Adult height for women with this condition ranges from 4 feet, 3 inches to 5 feet, 2 inches.

An eye abnormality called microspherophakia is characteristic of Weill-Marchesani syndrome. This term refers to a small, sphere-shaped lens, which is associated with nearsightedness (myopia) that worsens over time. The lens also may be positioned abnormally within the eye (ectopia lentis). Many people with Weill-Marchesani syndrome develop glaucoma, an eye disease that increases the pressure in the eye and can lead to blindness.

Occasionally, heart defects or an abnormal heart rhythm can occur in people with Weill-Marchesani syndrome.