MedGen

A disorder that results from a chromosomal abnormality. [from NCI]

Genetic diseases are diseases in which inherited genes predispose to increased risk. The genetic disorders associated with cancer often result from an alteration or mutation in a single gene. The diseases range from rare dominant cancer family syndrome to familial tendencies in which low-penetrance genes may interact with other genes or environmental factors to induce cancer. Research may involve clinical, epidemiologic, and laboratory studies of persons, families, and populations at high risk of these disorders. [from NCI]

An X-linked intellectual deficiency in which not enough information is known, reported or published to indicate whether a gene causes non-syndromic or syndromic presentations. [from MONDO]

A mode of inheritance that is observed for traits related to a gene encoded on the X chromosome. [from HPO]

Any non-syndromic X-linked intellectual disability in which the cause of the disease is a mutation in the TSPAN7 gene. [from MONDO]

Nonsyndromic mental retardation with speech disorders. [from MCA/MR]

Impaired mental functioning occurs as an isolated feature or as part of many syndromes listed in the X-linked catalog. Impaired intellectual development that is not associated with other distinguishing features is referred to as 'nonspecific.' The Human Gene Mapping Nomenclature Committee (Mulley et al., 1992) proposed to designate each newly reported apparently unique X-linked mental retardation (MRX) family with gene symbols (e.g., MRX1, MRX2) if a minimal lod score of 2.0 was demonstrated between the MR locus and one or more X chromosome markers. [from OMIM]

Autism, the prototypic pervasive developmental disorder (PDD), is usually apparent by 3 years of age. It is characterized by a triad of limited or absent verbal communication, a lack of reciprocal social interaction or responsiveness, and restricted, stereotypical, and ritualized patterns of interests and behavior (Bailey et al., 1996; Risch et al., 1999). 'Autism spectrum disorder,' sometimes referred to as ASD, is a broader phenotype encompassing the less severe disorders Asperger syndrome (see ASPG1; 608638) and pervasive developmental disorder, not otherwise specified (PDD-NOS). 'Broad autism phenotype' includes individuals with some symptoms of autism, but who do not meet the full criteria for autism or other disorders. Mental retardation coexists in approximately two-thirds of individuals with ASD, except for Asperger syndrome, in which mental retardation is conspicuously absent (Jones et al., 2008). Genetic studies in autism often include family members with these less stringent diagnoses (Schellenberg et al., 2006). Levy et al. (2009) provided a general review of autism and autism spectrum disorder, including epidemiology, characteristics of the disorder, diagnosis, neurobiologic hypotheses for the etiology, genetics, and treatment options. [from OMIM]