Mixed Connective Tissue Disease (MCTD)


MCTD develops as RNP (ribonucleoprotein) molecules are attacked by antibodies, inhibiting the production of messenger RNA. The body’s fibers that help to establish its framework and physical support (connective tissues) are also attacked.

Often referred to as an overlap disease, MCTD presents with signs and symptoms that can also look like several other conditions (including lupus, scleroderma, and polymyositis). It is a disease that presents different symptoms of different diseases over the course of several years but typically afflicts the hands early on. 

Common Symptoms

Red/reddish-brown rash patches over the knuckles, increased fatigue/mild fever, Raynaud’s phenomenon (cold/numb fingers/toes), swelling of the fingers or hands, muscle and joint pain/swelling/deformities, organs (kidneys, heart, and lungs) can be afflicted later in the progression of the disease, chest pain, stomach inflammation, dyspnea (trouble with breathing), high erythrocyte sedimentation rate, and dry mouth/eyes.

Risk Factors and Prevalence

While MCTD can develop in anyone, females under the age of 50 are most commonly afflicted.


  1. Article Sources
    1. Mayo Clinic Staff. (2020, June 2). Mixed connective tissue disease. Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/mixed-connective-tissue-disease/symptoms-causes/syc-20375147

    2. NORD (National Organization for Rare Disorders). (2017, July 5). Mixed Connective Tissue Disease (MCTD). NORD (National Organization for Rare Disorders). https://rarediseases.org/rare-diseases/mixed-connective-tissue-disease-mctd/.  

    3. U.S. Department of Health and Human Services. (n.d.). Mixed connective tissue disease. Genetic and Rare Diseases Information Center. https://rarediseases.info.nih.gov/diseases/7051/mixed-connective-tissue-disease