Currently, MCTD is diagnosed by the presence of anti-RNP antibodies, Raynaud's phenomenon, diffuse hand edema (“puffy hands”), and at least two of the following symptoms: arthritis, myositis, leukopenia, esophageal dysmotility, pleuritis, pericarditis, interstitial lung disease, or pulmonary hypertension (4). This evidence concerns the gene RNPC3 and mixed connective tissue disease.