Improved definition of growing pains: A common familial primary pain disorder of early childhood

Abstract

Growing pains is a highly prevalent genetically influenced primary pain disorder of early childhood. Growing pains, as commonly diagnosed, is associated with restless legs syndrome in individuals over time, in families, and in population samples. The reason for this association had not previously been clarified. This twin family study has shown that growing pains is confounded by painful restless legs syndrome, and that an exclusion clause, urge to move the legs, results in a purer phenotype which retains genetic influence. On the basis of results from this study, new criteria for the diagnosis of growing pains are proposed. Growing pains, a highly prevalent primary pain disorder of childhood, has been associated with restless legs syndrome in individuals over time, in families and in population samples. This conundrum has been clarified by the evidence in this twin family study that growing pains, as previously defined, has been confounded by symptoms of restless legs syndrome. An exclusion clause of urge to move the legs has resulted in criteria for a purer phenotype which retains evidence of heritability.