| Webbed neck | |
|---|---|
| Other names | Pterygium colli deformity |
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| Teenage girl with Turner syndrome and webbed neck | |
| Specialty | Medical genetics |
A webbed neck, or pterygium colli, is a congenital skin fold that runs along the sides of the neck down to the shoulders. There are many variants.
On babies, webbed neck may look like loose folds of skin on the neck. As the child grows, the skin may stretch out to look like there is little or no neck.[ citation needed ]
It is a feature of Turner syndrome [1] (only found in girls) and Noonan syndrome, [2] as well as the rarer Klippel–Feil syndrome, [3] or Diamond–Blackfan anemia. [4]
Turner syndrome (TS), commonly known as 45,X, or 45,XO, is a chromosomal disorder in which cells have only one X chromosome or are partially missing an X chromosome leading to the complete or partial deletion of the pseudoautosomal regions in the affected X chromosome. Most people have two sex chromosomes. The chromosomal abnormality is often present in just some cells, in which case it is known as Turner syndrome with mosaicism. 45,X0 with mosaicism can occur in males or females, but Turner syndrome without mosaicism only occurs in females. Signs and symptoms vary among those affected but often include additional skin folds on the neck, arched palate, low-set ears, low hairline at the nape of the neck, short stature, and lymphedema of the hands and feet. Typically, those affected do not develop menstrual periods or mammary glands without hormone treatment and are unable to reproduce without assistive reproductive technology. Small chin (micrognathia), loose folds of skin on the neck, slanted eyelids and prominent ears are found in Turner syndrome, though not all will show it. Heart defects, Type II diabetes, and hypothyroidism occur in the disorder more frequently than average. Most people with Turner syndrome have normal intelligence; however, many have problems with spatial visualization that may be needed in order to learn mathematics. Ptosis and conductive hearing loss also occur more often than average.
Fanconi anemia (FA) is a rare, autosomal recessive, genetic disease resulting in impaired response to DNA damage in the FA/BRCA pathway. Although it is a very rare disorder, study of this and other bone marrow failure syndromes has improved scientific understanding of the mechanisms of normal bone marrow function and development of cancer. Among those affected, the majority develop cancer, most often acute myelogenous leukemia (AML), myelodysplastic syndrome (MDS), and liver tumors. 90% develop aplastic anemia by age 40. About 60–75% have congenital defects, commonly short stature, abnormalities of the skin, arms, head, eyes, kidneys, and ears, and developmental disabilities. Around 75% have some form of endocrine problem, with varying degrees of severity. 60% of FA is FANC-A, 16q24.3, which has later onset bone marrow failure.
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.
Klippel–Feil syndrome (KFS), also known as cervical vertebral fusion syndrome, is a rare congenital condition characterized by the abnormal fusion of any two of the seven bones in the neck. It can result in a limited ability to move the neck and shortness of the neck, resulting in the appearance of a low hairline. Most people only have one or two of those symptoms so it may not be noticeable without medical imaging.
Microtia is a congenital deformity where the auricle is underdeveloped. A completely undeveloped auricle is referred to as anotia. Because microtia and anotia have the same origin, it can be referred to as microtia-anotia. Microtia can be unilateral or bilateral. Microtia occurs in 1 out of about 8,000–10,000 births. In unilateral microtia, the right ear is most commonly affected. It may occur as a complication of taking Accutane (isotretinoin) during pregnancy.
The VACTERL association refers to a recognized group of birth defects which tend to co-occur. This pattern is a recognized association, as opposed to a syndrome, because there is no known pathogenetic cause to explain the grouped incidence.
Diamond–Blackfan anemia (DBA) is a congenital erythroid aplasia that usually presents in infancy. DBA causes low red blood cell counts (anemia), without substantially affecting the other blood components, which are usually normal. This is in contrast to Shwachman–Bodian–Diamond syndrome, in which the bone marrow defect results primarily in neutropenia, and Fanconi anemia, where all cell lines are affected resulting in pancytopenia. There is a risk to develop acute myelogenous leukemia (AML) and certain other cancers.
Aplasia is a birth defect where an organ or tissue is wholly or largely absent. It is caused by a defect in a developmental process.
GATA-binding factor 1 or GATA-1 is the founding member of the GATA family of transcription factors. This protein is widely expressed throughout vertebrate species. In humans and mice, it is encoded by the GATA1 and Gata1 genes, respectively. These genes are located on the X chromosome in both species.
Pallister–Hall syndrome (PHS) is a rare genetic disorder that affects various body systems. The main features are a non-cancerous mass on the hypothalamus and extra digits (polydactylism). The prevalence of Pallister-Hall Syndrome is unknown; about 100 cases have been reported in publication.
Webbed toes is the informal and common name for syndactyly affecting the feet—the fusion of two or more digits of the feet. This is normal in many birds, such as ducks; amphibians, such as frogs; and some mammals, such as kangaroos. In humans it is rare, occurring once in about 2,000 to 2,500 live births: most commonly the second and third toes are webbed, which can reach partly or almost fully up the toe.
40S ribosomal protein S19 is a protein that in humans is encoded by the RPS19 gene.
Paired box protein Pax-1 is a protein that in humans is encoded by the PAX1 gene.
Congenital hypoplastic anemia is a congenital disorder that occasionally also includes leukopenia and thrombocytopenia and is characterized by deficiencies of red cell precursors.
Louis Klein Diamond was an American pediatrician. He is known as the "father of pediatric hematology".
Shwachman–Diamond syndrome (SDS), or Shwachman–Bodian–Diamond syndrome, is a rare congenital disorder characterized by exocrine pancreatic insufficiency, bone marrow dysfunction, skeletal and cardiac abnormalities and short stature. After cystic fibrosis (CF), it is the second most common cause of exocrine pancreatic insufficiency in children. It is associated with the SBDS gene and has autosomal recessive inheritance.
Parkes Weber syndrome (PWS) is a congenital disorder of the vascular system. It is an extremely rare condition, and its exact prevalence is unknown. It is named after British dermatologist Frederick Parkes Weber, who first described the syndrome in 1907.
Ribosomopathies are diseases caused by abnormalities in the structure or function of ribosomal component proteins or rRNA genes, or other genes whose products are involved in ribosome biogenesis.
Cervicocranial syndrome or is a combination of symptoms that are caused by an abnormality in the cervical vertebrae leading to improper function of cervical spinal nerves. Cervicocranial syndrome is either congenital or acquired. Cervicocranial syndrome may be caused by Chiari disease, Klippel-Feil malformation, osteoarthritis, and physical trauma. Treatment options include neck braces, pain medication and surgery. The quality of life for individuals suffering from Cervicocranial syndrome can improve through surgery.