The male patient aged between 60 and 65 years classified as having MCTD had an underlying disease of hepatitis C cirrhosis and presented with puffy fingers, pleuritis, lymphadenopathy, and mild sclerodactyly and tested positive for anti-U1-RNP antibodies, but with a low titer of ANA (homogeneous type). The gene discussed is BTG3; the disease is Pleuritis.