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Arachnodactyly is a physical condition in which the fingers are long, slender, and curved, resembling a spider's legs.
Alternative NamesDolichostenomelia; Spider fingers; Achromacria
ConsiderationsLong, slender fingers can be normal and not associated with any medical problems. In some cases, however, spider fingers can be a sign of an underlying disease.
Common Causes- Homocystinuria
- Marfan's syndrome
- Other rare genetic disorders
Note: Having long, slender fingers may be normal.
Call your health care provider ifSome children are born with arachnodactyly, although it may develop over time. Consult with your health care provider during a routine examination if your child has long, slender fingers and you are concerned that an underlying condition may exist.
What to expect at your health care provider's officeThe health care provider will perform a physical exam and ask questions about the patient's medical history, including:
- Time pattern
- When did you first notice the fingers being shaped like this?
- Family history
- Is there any family history of early death?
- Is there any family history of known hereditary disorders?
- Symptoms
- What other symptoms are also present?
- Have you noticed any other unusual things?
Diagnostic tests are usually not necessary unless a hereditary disorder is suspected.
Wiki User
∙ 13y ago
Wiki User
∙ 12y agoArachnodactyly is a condition in which the fingers are long, slender, and curved. They look like a spider's legs.
Alternative NamesDolichostenomelia; Spider fingers; Achromacria
ConsiderationsLong, slender fingers can be normal and not associated with any medical problems. In some cases, however, spider fingers can be a sign of an underlying disease.
Common Causes- Homocystinuria
- Marfan syndrome
- Other rare genetic disorders
Note: Having long, slender fingers may be normal.
Call your health care provider ifSome children are born with arachnodactyly, although it may develop over time. Consult with your health care provider during a routine examination if your child has long, slender fingers and you are concerned that an underlying condition may exist.
What to expect at your health care provider's officeThe health care provider will perform a physical exam and ask questions about the patient's medical history, including:
- Time pattern
- When did you first notice the fingers being shaped like this?
- Family history
- Is there any family history of early death?
- Is there any family history of known hereditary disorders?
- Symptoms
- What other symptoms are also present?
- Have you noticed any other unusual things?
Diagnostic tests are usually not necessary unless a hereditary disorder is suspected.
Reviewed ByReview Date: 02/02/2012
Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
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What is arachnodactyly?
Arachnodactyly-- A condition characterized by abnormally long and slender fingers and toes.
What is an inherited syndrome marked by a tall thin body with arachnodactyly?
Marfan syndrome
What is the medical term meaning long fingers?
Arachnodactyly is the medical term meaning long fingers.
What other name is Marfan syndrome known by?
Marfan syndrome is sometimes called arachnodactyly, which means "spider-like fingers" in Greek, since one of the characteristic signs of the disease is disproportionately long fingers and toes.
What is morphan's syndrome?
what is morphan syndromwhat is morphan syndromMarfan syndromeA connective tissue, multisystemic disorder characterized by skeletal changes (arachnodactyly ; long limbs, joint laxity, pectus), cardiovascular defects (aortic aneurysm which may dissect, mitral valve prolapse), and ectopia lentis; autosomal dominant inheritance, caused by mutation in the fibrillin-1 gene (FBN1) on chromosome 15q.
Does marfan syndrome affect the aorta?
Yes. Marfan syndrome is a congenital disorder affecting the formation of fibrillin. In Marfan syndrome, the abnormal fibrillin is responsible for many of the findings of the disease. Hyperextensibility/hyperelasticity of joints is one of the hallmark signs. Pectus excavatum is another. People with Marfan syndrome are typically very tall and thin, with very long fingers and toes (arachnodactyly). The fibrillin defect also affects the blood vessels, especially the large arteries, such as the aorta. Disordered fibrillin production causes these arteries to be weaker than normal, predisposing patients with Marfan syndrome to aortic dissections and rupture. This the major cause of death for patients with Marfan syndrome.
What may cause Marfan syndrome?
Marfan syndrome is an autosomal dominant condition caused by a genetic mutation. The mutation occurs on chromosome 15 and affects the gene that encodes a protein called fibrillin-1. Over 100 mutations have been described, all of which impair the function of fibrillin-1. The precise reasons for the mutations are unknown. How the mutation manifests as the Marfan syndrome is also uncertain. There is mounting evidence that the fibrillin-1 defect allows for unabated activity of transforming growth factor-beta (TGF-beta), which causes the clinical manifestations of the syndrome (eg, hyperextensible joints, arachnodactyly, dislocation of the lens, aortic aneurysm). Because the condition is inherited in an autosomal dominant pattern, a parent with Marfan syndrome has a 50% chance of passing the defective gene on to his/her offspring. Some diseases are also associated with features that resemble Marfan syndrome. For example, multiple endocrine neoplasia (MEN) type III is associated with what's been called a marfanoid habitus -- patients commonly have the elongated axial bones and hyperextensible joints seen in true Marfan syndrome. MEN-III is caused by a mutation in the RET gene on chromosome 10. It is inherited in an autosomal dominant pattern.
What is the genetic cause of Marfan syndrome?
Marfan syndrome is a disorder of the connective tissue. Connective tissue provides strength and flexibility to structures throughout the body such as bones, ligaments, muscles, the walls of blood vessels, and heart valves. It is caused by a mutation in fibrillin, which decreases fibrillin production and increases TGF-B production. 90-95% of people with Marfan syndrome are able to identify their mutation on FBN1. The other 5-10% may have a mutation on another gene that affects the production of fibrillin which we have not yet discovered. Marfan syndrome affects most organs and tissues, especially the skeleton, lungs, eyes, heart, and the large blood vessel that distributes blood from the heart to the rest of the body (the aorta). The signs and symptoms of Marfan syndrome vary widely in severity, timing of onset, and rate of progression. Affected individuals often are tall (as compared to unaffected family members) and slender, have elongated fingers and toes (arachnodactyly), and have an arm span that exceeds their body height. Other common features include unusually flexible joints, a long and narrow face, a highly arched roof of the mouth, crowded teeth, an abnormal curvature of the spine (scoliosis), and either a sunken chest (pectus excavatum) or a protruding chest (pectus carinatum). About half of all people with Marfan syndrome have vision problems caused by a dislocated lens (ectopia lentis) in one or both eyes, and most have some degree of nearsightedness (myopia). Clouding of the lens (cataract) may occur early on, even in childhood, and increased pressure within the eye (glaucoma) occurs more frequently in people with Marfan syndrome than in those without the condition.
Who discovered the Marfan Syndrome?
Antione B. MarfanMarfan syndrome was first described by a French doctor named Antione B. Marfan, who reported that one of his patients, Gabrielle, had especially long fingers (he called this arachnodactyly, or spider-fingers), skeletal abnormalities (including arms that were disproportionately long), and high, arched pallets. He also noticed spine defects. Antione noted that these traits seemed to be inherited, and it is now certain that Marfan syndrome is a hereditary disorder, and the gene for it is autosomal dominant A dominant gene is one that will overwrite other genes so that only one is required for the trait that that particular gene carries to be expressed. A person who inherits a dominant gene from one parent will automatically have the trait that the gene produces, unlike with recessive genes in which a gene for the trait must be inherited from each parent for the trait to show. Autosomal means that the gene is on a non-sex chromosome. There are 46 chromosomes in every human cell, and they make 23 pairs, each one connected by a centrome. The 23rd pair consists of the sex chromosomes.The gene for Marfan syndrome is located on chromosome fifteen. This gene causes the occurrence of too many microfibrillar fibers in the connective tissue, which results in a lack of flexibility in the body's tissues.Marfan syndrome almost always occurs as an inherited trait (about 75% of the time), but it can sometimes show up spontaneously in a person from a family that has never shown any signs of the disorder. Marfan syndrome, because it is dominant, will not skip generations (a recessive gene can be passed on without showing up for many generations, because two are needed for the trait to show, but if a dominant gene is going to show up, it will do so right away). Marfan syndrome has a 50% chance of being passed on to the children of an affected person. If the gene for Marfan syndrome is passed on, it will invariably show up, but the degree to which it shows its symptoms varies considerably, even within a family.Skeletal abnormalities that have been noticed in Marfan patients are a long face, an unusually tall stature, a short upper body in comparison to the lower body (because they have a short ribcage), and overgrown ribs. The latter results in chest deformities such as Pectus Excavatum (funnel chest) or Pectus Carnatum (pigeon breast). A wide pelvis, elongated skull, and prominent shoulder blades are other symptomsOne of the most distinctive characteristics of Marfan's Syndrome is unusually long arms, fingers, and toes. These skeletal problems can show up in either childhood or adolescence, and sometimes they do not show up at all Extremely mobile joints are another common characteristic.A good many patients have eye problems, like dislocated lenses, severe nearsightedness, iridodensis (a quivering motion of the iris), cataracts, detaching retinas, and glaucoma.The life-threatening risk to Marfan syndrome is that the aorta can grow to be too large, develop weak spots (aneurysms) and then tear (dissect). Without surgery, a person can die.People with Marfan's Syndrome often suffer from various lung problems as well.For more information www.marfan.org
Marfan syndrome?
DefinitionMarfan syndrome is a disorder of connective tissue, the tissue that strengthens the body's structures.Disorders of connective tissue affect the skeletal system, cardiovascular system, eyes, and skin.Causes, incidence, and risk factorsMarfan syndrome is caused by defects in a gene called fibrillin-1. Fibrillin-1 plays an important role as the building block for elastic tissue in the body.The gene defect also causes too much growth of the long bones of the body. This causes the tall height and long arms and legs seen in people with this syndrome. How this overgrowth happens is not well understood.Other areas of the body that are affected include:Lung tissueThe aorta, the main blood vessel that takes blood from the heart to the body may stretch or become weak (called aortic dilation or aortic aneurysm)The eyes, causing cataracts and other problemsThe skinTissue covering the spinal cordIn most cases, Marfan syndrome is inherited, which means it is passed down through families. However, up to 30% of cases have no family history. Such cases are called "sporadic." In sporadic cases, the syndrome is believed to result from a spontaneous new gene defect.SymptomsPeople with Marfan syndrome are usually tall with long, thin arms and legs and spider-like fingers -- a condition called arachnodactyly. When they stretch out their arms, the length of their arms is much greater than their height.Other symptoms include:A chest that sinks in or sticks out -- funnel chest (pectus excavatum) or pigeon breast (pectus carinatum)Coloboma of irisFlat feetHighly arched palate and crowded teethHypotoniaJoints that are too flexibleLearning disabilityMovement of the lens of the eye from its normal position (dislocation)NearsightednessSmall lower jaw (micrognathia)Spine that curves to one side (scoliosis)Thin, narrow faceSigns and testsThe doctor will perform a physical exam. There may be hypermobile joints and signs of:AneurysmCollapsed lungHeart valve problemsAn eye exam may show:Defects of the lens or corneaRetinal detachmentVision problemsThe following tests may be performed:EchocardiogramFibrillin-1 mutation testing (in some people)An echocardiogram should be done every year to look at the base of the aorta.TreatmentVision problems should be treated when possible. Take care to prevent scoliosis, especially during adolescence.Medicine to slow the heart rate may help prevent stress on the aorta. Avoid participating in competitive athletics and contact sports to avoid injuring the heart. Some people may need surgical replacement of the aortic root and valve.People with Marfan syndrome should take antibiotics before dental procedures to prevent endocarditis. Pregnant women with Marfan syndrome must be monitored very closely because of the increased stress on the heart and aorta.Support GroupsNational Marfan Foundation -- www.marfan.orgExpectations (prognosis)Heart-related complications may shorten the lifespan of people with this disease. However, many patients survive well into their 60s. Good care and surgery may extend the lifespan further.ComplicationsComplications may include:Aortic regurgitationAortic ruptureBacterial endocarditisDissecting aortic aneurysmEnlargement of the base of the aortaHeart failureMitral valve prolapseScoliosisVision problemsCalling your health care providerExperts recommend genetic counseling for couples with a history of this syndrome who wish to have children.PreventionSpontaneous new gene mutations leading to Marfan (less than 1/3 of cases) cannot be prevented. If you have Marfan syndrome, see your doctor at least once every year.ReferencesPyeritz RE. Inherited diseases of connective tissue. In: Goldman L, Ausiello D. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 281.Robinson LK, Fitzpatrick E. Marfan syndrome. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF. Nelson Textbook of Pediatrics. 18th ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 700.
Homocystinuria?
DefinitionHomocystinuria is an inherited disorder that affects the metabolism of the amino acidmethionine.Alternative NamesCystathionine beta synthase deficiencyCauses, incidence, and risk factorsHomocystinuria is inherited in families as an autosomal recessive trait. This means that the child must inherit the non-working gene from both parents to be seriously affected.Homocystinuria has several features in common with Marfan syndrome. Unlike Marfan syndrome, in which the joints tend to be "loose," in homocystinuria the joints tend to be "tight."SymptomsNewborn infants appear healthy. Early symptoms, if present at all, are not obvious.Symptoms may occur as mildly delayed development or failure to thrive. Increasing visual problems may lead to diagnosis of this condition.Other symptoms include:Chest deformities (pectus carinatum, pectus excavatum)Flush across the cheeksHigh arches of the feetKnock kneesLong limbsMental retardationNearsightednessPsychiatric disordersSpidery fingers (arachnodactyly)Tall, thin buildSigns and testsWhile performing a physical examination on the child, the health care provider may notice a tall, thin (Marfanoid) stature.Other signs include:Curved spine (scoliosis)Deformity of the chestDislocated lens of the eyeIf there is poor or double vision, an ophthalmologist should perform a dilated eye exam to look for dislocation of the lens or nearsightedness.There may be a history of frequent blood clots. Mental retardation, slightly low IQ, or psychiatric disease are common.Tests:Amino acid screen of blood and urineGenetic testingLiver biopsyand enzyme assaySkeletal x-raySkin biopsywith a fibroblast cultureStandard ophthalmic examTreatmentThere is no cure for homocystinuria. However, many people respond to high doses of vitamin B6 (also known as pyridoxine). Slightly less than half of patients respond to this treatment.Those who do respond will need to take vitamin B6 supplements for the rest of their lives. Those who do not respond need to eat a low-methionine diet. Most will need treatment with trimethylglycine (a medication also known as betaine).Neither a low-methionine diet nor medication will improve existing mental retardation. Medication and diet should be closely supervised by a physician with experience treating homocystinuria.A normal dose folic acid supplement and added cysteine (an amino acid) in the diet are helpful.Expectations (prognosis)Although no cure exists for homocystinuria, vitamin B6 therapy can help about half of people affected by the condition.If the diagnosis is made while a patient is young, starting a low methionine diet quickly can prevent some mental retardation and other complications of the disease. For this reason, some states screen for homocystinuria in all newborns.Patients with persistent rises in blood homocysteine levels are at increased risk for blood clots. Clots can cause significant medical problems and shorten lifespan.ComplicationsMost serious complications result from blood clots. These episodes can be life threatening.Dislocated lenses of the eyes can severely impair vision. Lens replacement surgery should be considered.Mental retardation is a serious consequence of the disease. However, it can be lessened if diagnosed early.Calling your health care providerCall your health care provider if you or a family member shows symptoms of this disorder, particularly if there is a family history of homocystinuria. Also call if you have a family history and are planning to have children.PreventionGenetic counseling is recommended for prospective parents with a family history of homocystinuria. Intrauterine diagnosis of homocystinuria is available. This involves culturing amniotic cells or chorionic villi to test for cystathionine synthase (the enzyme that is missing in homocystinuria).If there are known specific genetic mutations in the parents or family, samples from chorionic villus samplingor amniocentesiscan be used to test for these mutations.ReferencesRezvani I. Defects in metabolism of amino acids. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF. Nelson Textbook of Pediatrics. 18th ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 85.
