A professor of pathological anatomy at the University of Palermo, Franco claims that the model who sat for Da Vinci's Mona Lisa (Louvre, Paris) had dangerously high cholesterol. He made that diagnosis after spotting signs of xanthelasma -- a build up of yellowish fatty acids under the skin - under her left eye, as well as subcutaneous lipomas, benign tumors composed of fatty tissue, on her hands.
His study of other masterpieces convinced Franco that the young nobleman in Sandro Botticelli's Portrait of a Young Man (National Gallery, Washington) was probably afflicted with Marfan syndrome. Franco believes that the young man’s unnaturally long, thin fingers are a tell-tale indicator of the rare condition that affects connective tissue and can result in a sudden, early death.
But I’m skeptical when he suggests that the long-fingered hands of the woman who posed in the 1530s for Parmigianino's Madonna With the Long Neck (Uffizi, Florence) indicate that she too suffered from Marfans. Parmigianino was a Mannnerist painter and Mannerists were all about exaggeration. In fact, Wikipedia says, “Mannerism makes itself known by elongated proportions” and that very same Madonna With the Long Neck is shown as an example of mannerist artificiality!
On the other hand, Franco seems more credible when he suggests that Dutch magical realist Dick Ket unwittingly traced the progression of his illness in his work. Ket, who died of a congenital heart defect at the age of 37 in 1940, left behind 40 self-portraits. One of these, painted in the year before his death, shows the artist with swollen fingertips, a common side effect of several heart and lung complaints. "In a painting seven years before, his fingers are less deformed," Franco said. "But it shows an abnormal swelling of the veins on his neck -- a sign of the same syndrome, in its initial phase."