|Catalog of all known human genes and genetic phenotypes.
|Genes, genetic disorders, phenotypic traits
|Johns Hopkins University School of Medicine
Online Mendelian Inheritance in Man (OMIM) is a continuously updated catalog of human genes and genetic disorders and traits, with a particular focus on the gene-phenotype relationship. As of 28 June 2019 [update] , approximately 9,000 of the over 25,000 entries in OMIM represented phenotypes; the rest represented genes, many of which were related to known phenotypes.
OMIM is the online continuation of Victor A. McKusick's Mendelian Inheritance in Man (MIM), which was published in 12 editions between 1966 and 1998.Nearly all of the 1,486 entries in the first edition of MIM discussed phenotypes.
MIM/OMIM is produced and curated at the Johns Hopkins School of Medicine (JHUSOM). OMIM became available on the internet in 1987 under the direction of the Welch Medical Library at JHUSOM with financial support from the Howard Hughes Medical Institute. From 1995 to 2010, OMIM was available on the World Wide Web with informatics and financial support from the National Center for Biotechnology Information. The current OMIM website (OMIM.org), which was developed with funding from JHUSOM, is maintained by Johns Hopkins University with financial support from the National Human Genome Research Institute.
The content of MIM/OMIM is based on selection and review of the published peer-reviewed biomedical literature. Updating of content is performed by a team of science writers and curators under the direction of Ada Hamosh at the McKusick-Nathans Institute of Genetic Medicine of Johns Hopkins University. While OMIM is freely available to the public, it is designed for use primarily by physicians and other health care professionals concerned with genetic disorders, by genetics researchers, and by advanced students in science and medicine.
The database may be used as a resource for locating literature relevant to inherited conditions,and its numbering system is widely used in the medical literature to provide a unified index for genetic diseases.
Each OMIM entry is given a unique six-digit identifieras summarized below:
In cases of allelic heterogeneity, the MIM number of the entry is followed by a decimal point and a unique 4-digit number specifying the variant.For example, allelic variants in the HBB gene (141900) are numbered 141900.0001 through 141900.0538.
Because OMIM has responsibility for the classification and naming of genetic disorders, these numbers are stable identifiers of the disorders.
Symbols preceding MIM numbersindicate the entry category:
An allele, or allelomorph, is a variant of the sequence of nucleotides at a particular location, or locus, on a DNA molecule.
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.
In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome. The first variant is termed dominant and the second is called recessive. This state of having two different variants of the same gene on each chromosome is originally caused by a mutation in one of the genes, either new or inherited. The terms autosomal dominant or autosomal recessive are used to describe gene variants on non-sex chromosomes (autosomes) and their associated traits, while those on sex chromosomes (allosomes) are termed X-linked dominant, X-linked recessive or Y-linked; these have an inheritance and presentation pattern that depends on the sex of both the parent and the child. Since there is only one copy of the Y chromosome, Y-linked traits cannot be dominant or recessive. Additionally, there are other forms of dominance, such as incomplete dominance, in which a gene variant has a partial effect compared to when it is present on both chromosomes, and co-dominance, in which different variants on each chromosome both show their associated traits.
Victor Almon McKusick was an American internist and medical geneticist, and Professor of Medicine at the Johns Hopkins Hospital, Baltimore. He was a proponent of the mapping of the human genome due to its use for studying congenital diseases. He is well known for his studies of the Amish. He was the original author and, until his death, remained chief editor of Mendelian Inheritance in Man (MIM) and its online counterpart Online Mendelian Inheritance in Man (OMIM). He is widely known as the "father of medical genetics".
Aniridia is the absence of the iris, a muscular structure that opens and closes the pupil to allow light into the eye. It is also responsible for eye color. Without it, the central eye appears all black. It can be congenital, in which both eyes are usually involved, or caused by a penetrant injury. Isolated aniridia is a congenital disorder that is not limited to a defect in iris development, but is a panocular condition with macular and optic nerve hypoplasia, cataract, and corneal changes. Vision may be severely compromised and the disorder is frequently associated with some ocular complications: nystagmus, amblyopia, buphthalmos, and cataract. Aniridia in some individuals occurs as part of a syndrome, such as WAGR syndrome, or Gillespie syndrome.
Human genetics is the study of inheritance as it occurs in human beings. Human genetics encompasses a variety of overlapping fields including: classical genetics, cytogenetics, molecular genetics, biochemical genetics, genomics, population genetics, developmental genetics, clinical genetics, and genetic counseling.
Oculocutaneous albinism is a form of albinism involving the eyes, the skin, and the hair. Overall, an estimated 1 in 20,000 people worldwide are born with oculocutaneous albinism. OCA is caused by mutations in several genes that control the synthesis of melanin within the melanocytes. Seven types of oculocutaneous albinism have been described, all caused by a disruption of melanin synthesis and all autosomal recessive disorders. Oculocutaneous albinism is also found in non-human animals.
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.
Acromicric dysplasia is an extremely rare inherited disorder characterized by abnormally short hands and feet, growth retardation and delayed bone maturation leading to short stature. Most cases have occurred randomly for no apparent reason (sporadically). However, autosomal dominant inheritance has not been ruled out.
Acrocephalosyndactyly is a group of autosomal dominant congenital disorders characterized by craniofacial (craniosynostosis) and hand and foot (syndactyly) abnormalities. When polydactyly is present, the classification is acrocephalopolysyndactyly. Acrocephalosyndactyly is mainly diagnosed postnatally, although prenatal diagnosis is possible if the mutation is known to be within the family genome. Treatment often involves surgery in early childhood to correct for craniosynostosis and syndactyly.
Cerebrotendinous xanthomatosis, also called cerebral cholesterosis, is an autosomal recessive form of xanthomatosis. It falls within a group of genetic disorders called the leukodystrophies.
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.
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.
Pontocerebellar hypoplasia (PCH) is a heterogeneous group of rare neurodegenerative disorders caused by genetic mutations and characterised by progressive atrophy of various parts of the brain such as the cerebellum or brainstem. Where known, these disorders are inherited in an autosomal recessive fashion. There is no known cure for PCH.
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.
Oligogenic inheritance describes a trait that is influenced by a few genes. Oligogenic inheritance represents an intermediate between monogenic inheritance in which a trait is determined by a single causative gene, and polygenic inheritance, in which a trait is influenced by many genes and often environmental factors.
Mendelian traits behave according to the model of monogenic or simple gene inheritance in which one gene corresponds to one trait. Discrete traits with simple Mendelian inheritance patterns are relatively rare in nature, and many of the clearest examples in humans cause disorders. Discrete traits found in humans are common examples for teaching genetics.
GeneMatcher is an online service and database that aims to match clinicians studying patients with a rare disease presentation based on genes of interest. When two or more clinicians submit the same gene to the database, the service matches them together to allow them to compare cases. It also allows matching genes from animal models to human cases. The service aims to establish novel relationships between genes and genetic diseases of unknown cause.
Shrawan Kumar, is an Indian-American geneticist, working in the fields of molecular and population genetics. He is known for his contributions in the discovery of two genes related to Branchio-oto-renal syndrome (BOR) and Autosomal Dominant Polycystic Kidney Disease (ADPKD2).