Type : Phenotype or locus, molecular basis unknown;
Alternative titles and symbols : MRX20; Mental retardation, X-linked 20;
Description : Impaired mental functioning occurs as an isolated feature or as part of many syndromes
listed in the X-linked catalog. Mental retardation 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 1 or more
X chromosome markers.;