Schimke syndrome | |
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Other names |
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Schimke syndrome is a rare autosomal recessive disorder. [2]
The disorder was first described in 1971 by Schimke. [3]
Most people with this disorder are diagnosed at age 6. [4]
Tests for mutations in the SMARCAL1 can confirm the diagnosis. [5]
The exact prevalence is unknown but is said to occur in 1 in a million births in North America. [5] The disorder is said to occur in 1 in 1 million or 1 in 3 million people in North America. [6]
Achondroplasia is a genetic disorder with an autosomal dominant pattern of inheritance whose primary feature is dwarfism. It is the most common cause of dwarfism and affects about 1 in 27,500 people. In those with the condition, the arms and legs are short, while the torso is typically of normal length. Those affected have an average adult height of 131 centimetres for males and 123 centimetres (4 ft) for females. Other features can include an enlarged head with prominent forehead and underdevelopment of the midface. Complications can include sleep apnea or recurrent ear infections. Achondroplasia includes the extremely rare short-limb skeletal dysplasia with severe combined immunodeficiency.
Dwarfism is a condition of people and animals marked by unusually small size or short stature. In humans, it is sometimes defined as an adult height of less than 147 centimetres, regardless of sex; the average adult height among people with dwarfism is 120 centimetres (4 ft). Disproportionate dwarfism is characterized by either short limbs or a short torso. In cases of proportionate dwarfism, both the limbs and torso are unusually small. Intelligence is usually normal, and most people with it have a nearly normal life expectancy. People with dwarfism can usually bear children, although there are additional risks to the mother and child depending upon the underlying condition.
Macrocephaly is a condition in which circumference of the human head is abnormally large. It may be pathological or harmless, and can be a familial genetic characteristic. People diagnosed with macrocephaly will receive further medical tests to determine whether the syndrome is accompanied by particular disorders. Those with benign or familial macrocephaly are considered to have megalencephaly.
Multiple endocrine neoplasia is a condition which encompasses several distinct syndromes featuring tumors of endocrine glands, each with its own characteristic pattern. In some cases, the tumors are malignant, in others, benign. Benign or malignant tumors of nonendocrine tissues occur as components of some of these tumor syndromes.
Hyperpigmentation is the darkening of an area of skin or nails caused by increased melanin.
Cleidocranial dysostosis (CCD), also called cleidocranial dysplasia, is a birth defect that mostly affects the bones and teeth. The collarbones are typically either poorly developed or absent, which allows the shoulders to be brought close together. The front of the skull often does not close until later, and those affected are often shorter than average. Other symptoms may include a prominent forehead, wide set eyes, abnormal teeth, and a flat nose. Symptoms vary among people; however, intelligence is typically unaffected.
Anodontia is a rare genetic disorder characterized by the congenital absence of all primary or permanent teeth. It is divided into two subsections, complete absence of teeth or only some absence of teeth. It is associated with the group of skin and nerve syndromes called the ectodermal dysplasias. Anodontia is usually part of a syndrome and seldom occurs as an isolated entity. There is usually no exact cause for anodontia. The defect results in the dental lamina obstruction during embryogenesis due to local, systemic and genetic factors.
Dentin dysplasia (DD) is a rare genetic developmental disorder affecting dentine production of the teeth, commonly exhibiting an autosomal dominant inheritance that causes malformation of the root. It affects both primary and permanent dentitions in approximately 1 in every 100,000 patients. It is characterized by the presence of normal enamel but atypical dentin with abnormal pulpal morphology. Witkop in 1972 classified DD into two types which are Type I (DD-1) is the radicular type, and type II (DD-2) is the coronal type. DD-1 has been further divided into 4 different subtypes (DD-1a,1b,1c,1d) based on the radiographic features.
Monostotic fibrous dysplasia is a form of fibrous dysplasia where only one bone is involved. It comprises a majority of the cases of fibrous dysplasia.
SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily A-like protein 1 is a protein that in humans is encoded by the SMARCAL1 gene.
Focal dermal hypoplasia is a form of ectodermal dysplasia. It is a multisystem disorder characterized primarily by skin manifestations to the atrophic and hypoplastic areas of skin which are present at birth. These defects manifest as yellow-pink bumps on the skin and pigmentation changes. The disorder is also associated with shortness of stature and some evidence suggests that it can cause epilepsy.
Trevor disease, also known as dysplasia epiphysealis hemimelica and Trevor's disease, is a congenital bone developmental disorder. There is 1 case per million population. The condition is three times more common in males than in females.
Progressive osseous heteroplasia is a cutaneous condition characterized by cutaneous or subcutaneous ossification.
Opsismodysplasia is a type of skeletal dysplasia first described by Zonana and associates in 1977, and designated under its current name by Maroteaux (1984). Derived from the Greek opsismos ("late"), the name "opsismodysplasia" describes a delay in bone maturation. In addition to this delay, the disorder is characterized by micromelia, particularly of the hands and feet, delay of ossification, platyspondyly, irregular metaphyses, an array of facial aberrations and respiratory distress related to chronic infection. Opsismodysplasia is congenital, being apparent at birth. It has a variable mortality, with some affected individuals living to adulthood. The disorder is rare, with an incidence of less than 1 per 1,000,000 worldwide. It is inherited in an autosomal recessive pattern, which means the defective (mutated) gene that causes the disorder is located on an autosome, and the disorder occurs when two copies of this defective gene are inherited. No specific gene has been found to be associated with the disorder. It is similar to spondylometaphyseal dysplasia, Sedaghatian type.
Kleeblattschaedel is a rare malformation of the head where there is a protrusion of the skull and broadening of the face. This condition is a severe type of craniosynostosis.
van Den Bosch syndrome is a rare X-linked syndrome like intellectual disability. It may be caused by a small X-chromosome deletion.
Angel-shaped phalango-epiphyseal dysplasia, also known as peripheral dysostosis, is a rare type of osteochondrodysplasia which is characterized by angel-shaped middle phalanges of the fingers and generalized metaphyseal dysplasia/delayed osseous age. Additional findings include joint hypermobility, hypodontia, and hip osteoarthritis. According to OMIM, 10 cases from multiple families have been described in medical literature. It is thought to be inherited in an autosomal dominant manner. According to ORPHA, 20 cases have been reported.
Acrocraniofacial dysostosis, also known as Kaplan Plauchu Fitch syndrome is a very rare hereditary disorder which is characterized by cranio-facial dysmorphisms, hearing loss, digital clubbing, and osseous anomalies. Only 2 cases have been described in medical literature.
Hall-Riggs syndrome is a rare genetic disorder that causes neurological issues and birth defects. People with Hall-Riggs syndrome usually have skeletal dysplasia, facial deformities, and intellectual disabilities. Only 8 cases from 2 families worldwide have been described in medical literature. It is an autosomal recessive genetic disorder, meaning both parents must carry the gene in order for their offspring to be affected.
Hypohidrotic/anhidrotic ectodermal dysplasia with immune deficiency is a rare genetic condition characterized by a combination of the features of ectodermal dysplasia alongside immunodeficiency.