Arachnodactyly | |
---|---|
Other names | Achromachia |
Bilateral arachnodactyly | |
Specialty | Medical genetics |
Complications | None |
Usual onset | Birth |
Duration | Life-long |
Causes | Mutations in the fibrillin-2 gene, in chromosome 5q23, or the fibrillin-1 gene, at chromosome 15q21.1 |
Arachnodactyly ("spider fingers") is a medical condition that is characterized by fingers and toes that are abnormally long and slender, in comparison to the palm of the hand and arch of the foot. In some cases, the thumbs of an individual with the condition are pulled inwards towards the palm. This condition is present at birth.
This feature can occur on its own with no underlying health problems, or it can be associated with certain medical conditions, including Marfan syndrome, [1] Ehlers–Danlos syndromes, [2] Loeys–Dietz syndrome, and homocystinuria. [3] It is also seen in congenital contractural arachnodactyly, [4] which is caused by mutation in the gene encoding fibrillin-2 on chromosome 5q23. [5]
It remains unconfirmed whether composer Sergei Rachmaninoff's abnormally large reach on a piano was a result of arachnodactyly due to Marfan syndrome, as the pianist exhibited no other signs of the disease. [6]
Marfan syndrome (MFS) is a multi-systemic genetic disorder that affects the connective tissue. Those with the condition tend to be tall and thin, with long arms, legs, fingers, and toes. They also typically have exceptionally flexible joints and abnormally curved spines. The most serious complications involve the heart and aorta, with an increased risk of mitral valve prolapse and aortic aneurysm. The lungs, eyes, bones, and the covering of the spinal cord are also commonly affected. The severity of the symptoms is variable.
Noonan syndrome (NS) is a genetic disorder that may present with mildly unusual facial features, short height, congenital heart disease, bleeding problems, and skeletal malformations. Facial features include widely spaced eyes, light-colored eyes, low-set ears, a short neck, and a small lower jaw. Heart problems may include pulmonary valve stenosis. The breast bone may either protrude or be sunken, while the spine may be abnormally curved. Intelligence is often normal. Complications of NS can include leukemia.
Malouf syndrome is a congenital disorder that causes one or more of the following symptoms: intellectual disability, ovarian dysgenesis, congestive cardiomyopathy, broad nasal base, blepharoptosis, and bone abnormalities, and occasionally marfanoid habitus.
Microphthalmia, also referred as microphthalmos, is a developmental disorder of the eye in which one or both eyes are abnormally small and have anatomic malformations. Microphthalmia is a distinct condition from anophthalmia and nanophthalmia. Although sometimes referred to as 'simple microphthalmia', nanophthalmia is a condition in which the size of the eye is small but no anatomical alterations are present.
Connective tissue disease, also known as connective tissue disorder, or collagen vascular diseases, refers to any disorder that affects the connective tissue. The body's structures are held together by connective tissues, consisting of two distinct proteins: elastin and collagen. Tendons, ligaments, skin, cartilage, bone, and blood vessels are all made of collagen. Skin and ligaments contain elastin. The proteins and the body's surrounding tissues may suffer damage when these connective tissues become inflamed.
Achard syndrome is a syndrome consisting of arachnodactyly, receding lower jaw, and joint laxity limited to the hands and feet. Hypermobility and subluxations of the joints, increased lateral excursion of the patellas and other findings reflect the increased ligament laxity. It is clinically similar to Marfan syndrome.
Cohen syndrome is a very rare autosomal recessive genetic disorder with varied expression, characterised by obesity, intellectual disability, distinct craniofacial abnormalities and potential ocular dysfunction.
Dermatoglyphics is the scientific study of fingerprints, lines, mounts and shapes of hands, as distinct from the superficially similar pseudoscience of palmistry.
Mowat–Wilson syndrome is a rare genetic disorder that was clinically delineated by David R. Mowat and Meredith J. Wilson in 1998. The condition affects both males and females, has been described in various countries and ethnic groups around the world, and occurs in approximately 1 in 50,000–100,000 births.
The palpebral fissure is the elliptic space between the medial and lateral canthi of the two open eyelids. In simple terms, it is the opening between the eyelids. In adult humans, this measures about 10 mm vertically and 30 mm horizontally.
Camptodactyly is a medical condition that causes one or more digits to be permanently bent. It involves fixed flexion deformity of the proximal interphalangeal joints.
Congenital contractural arachnodactyly (CCA), also known as Beals–Hecht syndrome, is a rare autosomal dominant congenital connective tissue disorder. As with Marfan syndrome, people with CCA typically have an arm span that is greater than their height and very long fingers and toes. However, Beals and Hecht discovered in 1972 that, unlike Marfan's, CCA is caused by mutations to the fibrillin-2 (FBN2) gene rather than the fibrillin-1 (FBN1) gene.
Marfanoid is a constellation of signs resembling those of Marfan syndrome, including long limbs, with an arm span that is at least 1.03 of the height of the individual, and a crowded oral maxilla, sometimes with a high arch in the palate, arachnodactyly, and hyperlaxity.
Lujan–Fryns syndrome (LFS) is an X-linked genetic disorder that causes mild to moderate intellectual disability and features described as Marfanoid habitus, referring to a group of physical characteristics similar to those found in Marfan syndrome. These features include a tall, thin stature and long, slender limbs. LFS is also associated with psychopathology and behavioral abnormalities, and it exhibits a number of malformations affecting the brain and heart. The disorder is inherited in an X-linked dominant manner, and is attributed to a missense mutation in the MED12 gene. There is currently no treatment or therapy for the underlying MED12 malfunction, and the exact cause of the disorder remains unclear.
Ectrodactyly, split hand, or cleft hand involves the deficiency or absence of one or more central digits of the hand or foot and is also known as split hand/split foot malformation (SHFM). The hands and feet of people with ectrodactyly (ectrodactyls) are often described as "claw-like" and may include only the thumb and one finger with similar abnormalities of the feet.
Spondylo-meta-epiphyseal dysplasia (SMED) is a rare autosomal-recessive disease that causes skeletal disorders. SMED is thought to be caused by a mutation in the Discoidin Domain Receptor 2 (DDR2) gene.
Wiedemann–Rautenstrauch (WR) syndrome, also known as neonatal progeroid syndrome, is a rare autosomal recessive progeroid syndrome. There have been over 30 cases of WR. WR is associated with abnormalities in bone maturation, and lipids and hormone metabolism.
Munis Dundar is a professor of Medical Genetics and Head of the Medical Genetics Department at Erciyes University, Kayseri, Turkey. He is founder and head of the Medical Genetics Department at Erciyes University and has carried out various administrative tasks since 1996. He defined four genetic syndromes in the medical literature: the “Dundar Syndrome”, “Dundar Acropectoral Syndrome”, “Scoliosis, Blindness and Arachnodactyly Syndrome” and “Multiple Congenital Abnormalities and Mental Retardation Syndrome”. He has taken part as project coordinator and assistant investigator in many research projects and has prepared articles published in international journals since 1995. He is the president of EBTNA and representative from Turkey. He is also the editor-in-chief of The EuroBiotech Journal.
Dolichonychia is a medical condition in which the nail beds of the fingers and toes are abnormally long and slender, specifically, a finger nail index of 1.30 or more, it is a common feature in people with connective tissue disorders, such as Ehlers–Danlos syndromes, Marfan syndrome, and hypohidrotic ectodermal dysplasia., it often appears alongside arachnodactyly and/or dolichostenomelia, which is the condition of having long and slender fingers and toes.
Multiple congenital anomalies-hypotonia-seizures syndrome is a rare multi-systemic genetic disorder which is characterized by developmental delay, seizures, hypotonia and heart, urinary, and gastrointestinal abnormalities.