title: A fragile balance: FMR1 expression levels.
abstract: The FMR1 gene is involved in three different syndromes, the Fragile X syndrome, premature ovarian failure (POF) and the Fragile X-associated tremor/ataxia syndrome (FXTAS) at older age. Fragile X syndrome is caused by an expanded CGG repeat above 200 units in the FMR1 gene resulting in the absence of the FMR1 mRNA and protein. The FMR1 protein is proposed to act as a regulator of mRNA transport and/or translation that plays a role in synaptic maturation and function. POF and FXTAS are found in individuals with an expanded repeat between 50 and 200 CGGs and are associated with increased FMR1 mRNA levels. The presence of elevated FMR1 mRNA in all patients suggests that these syndromes may represent a gain-of-function effect from the elevated message levels. The level of FMR1 mRNA is in fragile balance and is therefore critical for normal functioning.
authors.affiliation: Department of Clinical Genetics, Erasmus MC, The Netherlands. b.oostra@erasmusmc.nl
authors.forename: Ben A
authors.initials: BA
authors.lastname: Oostra
authors.forename: Rob
authors.initials: R
authors.lastname: Willemsen
mesh_terms: D003712:Dendrites / Q000378:metabolism; D005260:Female; D051860:Fragile X Messenger Ribonucleoprotein 1; D005600:Fragile X Syndrome / Q000235:genetics*; D006580:Genetic Carrier Screening; D006801:Humans; D008297:Male; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000235:genetics*; D010641:Phenotype; D021381:Protein Transport; D012333:RNA, Messenger / Q000235:genetics; D016601:RNA-Binding Proteins; D018911:Trinucleotide Repeats
chemical_list: D051860:Fragile X Messenger Ribonucleoprotein 1; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; C497683:FMR1 protein, human