Snyder-Robinson syndrome

Snyder-Robinson syndrome is an extremely rare inherited genetic disorder characterised by muscular and skeletal abnormalities, varying degrees of intellectual disability, seizures and slow development. It is caused by a mutated SMS gene on the X chromosome, which carries instructions for the enzyme spermine synthase. That enzyme helps the body make spermine, a polyamine needed for cell division, tissue repair and programmed cell death, and the resulting shortage of spermine causes problems with development and brain function, although the exact mechanism is not understood. It affects only males and is also called Snyder-Robinson X-linked mental retardation syndrome and spermine synthase deficiency. About fifty people have been diagnosed worldwide since 1969. This entry is a reference record and not medical advice.