An autosome is any chromosome that is not a sex chromosome. The members of an autosome pair in a diploid cell have the same morphology, unlike those in allosomal pairs, which may have different structures. The DNA in autosomes is collectively known as atDNA or auDNA.
A genetic disorder is a health problem caused by one or more abnormalities in the genome. It can be caused by a mutation in a single gene (monogenic) or multiple genes (polygenic) or by a chromosomal abnormality. Although polygenic disorders are the most common, the term is mostly used when discussing disorders with a single genetic cause, either in a gene or chromosome. The mutation responsible can occur spontaneously before embryonic development, or it can be inherited from two parents who are carriers of a faulty gene or from a parent with the disorder. When the genetic disorder is inherited from one or both parents, it is also classified as a hereditary disease. Some disorders are caused by a mutation on the X chromosome and have X-linked inheritance. Very few disorders are inherited on the Y chromosome or mitochondrial DNA.
Waardenburg syndrome is a group of rare genetic conditions characterised by at least some degree of congenital hearing loss and pigmentation deficiencies, which can include bright blue eyes, a white forelock or patches of light skin. These basic features constitute type 2 of the condition; in type 1, there is also a wider gap between the inner corners of the eyes called telecanthus, or dystopia canthorum. In type 3, which is rare, the arms and hands are also malformed, with permanent finger contractures or fused fingers, while in type 4, the person also has Hirschsprung's disease. There also exist at least two types that can result in central nervous system (CNS) symptoms such as developmental delay and muscle tone abnormalities.
Salla disease (SD) is an autosomal recessive lysosomal storage disease characterized by early physical impairment and intellectual disability. It was first described in 1979, after Salla, a municipality in Finnish Lapland and is one of 40 Finnish heritage diseases.
Spondyloperipheral dysplasia is an autosomal dominant disorder of bone growth. The condition is characterized by flattened bones of the spine (platyspondyly) and unusually short fingers and toes (brachydactyly). Some affected individuals also have other skeletal abnormalities, short stature, nearsightedness (myopia), hearing loss, and mental retardation. Spondyloperipheral dysplasia is a subtype of collagenopathy, types II and XI.
Albinism-black lock-cell migration disorder is the initialism for the following terms and concepts that describe a condition affecting a person's physical appearance and physiology: (1) A – albinism, (2) B – black lock of hair, (3) C – cell migration disorder of the neurocytes of the gut, and (4) D – sensorineural deafness. The syndrome is caused by mutation in the endothelin B receptor gene (EDNRB).
Nijmegen breakage syndrome (NBS) is a rare autosomal recessive congenital disorder causing chromosomal instability, probably as a result of a defect in the double Holliday junction DNA repair mechanism and/or the synthesis dependent strand annealing mechanism for repairing double strand breaks in DNA.
Autosomal recessive multiple epiphyseal dysplasia (ARMED), also called epiphyseal dysplasia, multiple, 4 (EDM4), multiple epiphyseal dysplasia with clubfoot or –with bilayered patellae, is an autosomal recessive congenital disorder affecting cartilage and bone development. The disorder has relatively mild signs and symptoms, including joint pain, scoliosis, and malformations of the hands, feet, and knees.
Piebaldism refers to the absence of mature melanin-forming cells (melanocytes) in certain areas of the skin and hair. It is a rare autosomal dominant disorder of melanocyte development. Common characteristics include a congenital white forelock, scattered normal pigmented and hypopigmented macules and a triangular shaped depigmented patch on the forehead. There is nevertheless great variation in the degree and pattern of presentation, even within affected families. In some cases, piebaldism occurs together with severe developmental problems, as in Waardenburg syndrome and Hirschsprung's disease.
White sponge nevus (WSN) is an autosomal dominant condition of the oral mucosa. It is caused by a mutations in certain genes coding for keratin, which causes a defect in the normal process of keratinization of the mucosa. This results in lesions which are thick, white and velvety on the inside of the cheeks within the mouth. Usually, these lesions are present from birth or develop during childhood. The condition is entirely harmless, and no treatment is required.
Papillorenal syndrome is an autosomal dominant genetic disorder marked by underdevelopment (hypoplasia) of the kidney and colobomas of the optic nerve.
Naegeli–Franceschetti–Jadassohn syndrome (NFJS), also known as chromatophore nevus of Naegeli and Naegeli syndrome, is a rare autosomal dominant form of ectodermal dysplasia, characterized by reticular skin pigmentation, diminished function of the sweat glands, the absence of teeth and hyperkeratosis of the palms and soles. One of the most striking features is the absence of fingerprint lines on the fingers.
Vici syndrome, also called immunodeficiency with cleft lip/palate, cataract, hypopigmentation and absent corpus callosum, is a rare autosomal recessive congenital disorder characterized by albinism, agenesis of the corpus callosum, cataracts, cardiomyopathy, severe psychomotor retardation, seizures, immunodeficiency and recurrent severe infections. To date, about 50 cases have been reported.
Rothmund–Thomson syndrome (RTS) is a rare autosomal recessive skin condition.
Gap junction beta-6 protein (GJB6), also known as connexin 30 (Cx30) — is a protein that in humans is encoded by the GJB6 gene. Connexin 30 (Cx30) is one of several gap junction proteins expressed in the inner ear. Mutations in gap junction genes have been found to lead to both syndromic and nonsyndromic deafness. Mutations in this gene are associated with Clouston syndrome.
Woodhouse–Sakati syndrome, is a rare autosomal recessive multisystem disorder which causes malformations throughout the body, and deficiencies affecting the endocrine system.
Worth syndrome, also known as benign form of Worth hyperostosis corticalis generalisata with torus platinus, autosomal dominant osteosclerosis, autosomal dominant endosteal hyperostosis or Worth disease, is a rare autosomal dominant congenital disorder that is caused by a mutation in the LRP5 gene. It is characterized by increased bone density and benign bony structures on the palate.
Gillespie syndrome, also called aniridia, cerebellar ataxia and mental deficiency, is a rare genetic disorder. The disorder is characterized by partial aniridia, ataxia, and, in most cases, intellectual disability. It is heterogeneous, inherited in either an autosomal dominant or autosomal recessive manner. Gillespie syndrome was first described by American ophthalmologist Fredrick Gillespie in 1965.
Lethal congenital contracture syndrome 1 (LCCS1), also called Multiple contracture syndrome, Finnish type, is an autosomal recessive genetic disorder characterized by total immobility of a fetus, detectable at around the 13th week of pregnancy. LCCS1 invariably leads to prenatal death before the 32nd gestational week. LCCS1 is one of 40 Finnish heritage diseases. It was first described in 1985 and since then, approximately 70 cases have been diagnosed.
Parastremmatic dwarfism is a rare bone disease that features severe dwarfism, thoracic kyphosis, a distortion and twisting of the limbs, contractures of the large joints, malformations of the vertebrae and pelvis, and incontinence. The disease was first reported in 1970 by Leonard Langer and associates; they used the term parastremmatic from the Greek parastremma, or distorted limbs, to describe it. On X-rays, the disease is distinguished by a "flocky" or lace-like appearance to the bones. The disease is congenital, which means it is apparent at birth. It is caused by a mutation in the TRPV4 gene, located on chromosome 12 in humans. The disease is inherited in an autosomal dominant manner.
