A large number of loci for genetic diseases have been mapped on the human genome and a group of hereditary diseases among them have thus far proven unsuccessful to clone. It is conceivable that such "unclonable" diseases are not linked to abnormalities of protein coding genes (PCGs), but of non-coding RNAs (ncRNAs). We developed a novel approach termed OMiR (OMIM and miRNAs), to test whether microRNAs (miRNAs) exhibit any associations with mapped genetic diseases not yet associated with a PCG. We found that "orphan" genetic disease loci were proximal to miRNA loci more frequently than to loci for which the responsible protein coding gene is known, thus suggesting that miRNAs might be the elusive culprits. Our findings indicate that inclusion of miRNAs among the candidate genes to be considered could assist geneticists in their hunt for disease genes, particularly in the case of rare diseases. © 2010 Elsevier Inc.