WARSAW  The heart of Frederic Chopin, one of the world's most cherished musical geniuses, could hold the secret to his untimely death. The renowned 19th century Polish-French pianist and composer died at the age of 39, of what is believed to be tuberculosis. But leading Polish medical experts are betting that DNA tests on his heart perfectly preserved in what appears to be cognac could prove he suffered from cystic fibrosis. Their request to Poland's culture ministry for tissue samples to check for the CFTR gene marking cystic fibrosis sufferers has, however, sparked mixed feelings over the prospect of picking over a national icon. "For where your treasure is, there your heart will be also," reads the biblical passage inscribed on a pillar in Warsaw's sprawling and ornate baroque Church of the Holy Cross. There, inside a crystal urn filled with alcohol lies Chopin's heart, brought home in 1849 as he had wished by his elder sister Ludwika from Paris, where the rest of his remains lie in the Pere Lachaise cemetery. Leading Polish cystic fibrosis specialist Wojciech Cichy said the symptoms Chopin suffered throughout his life were typical of cystic fibrosis, a genetic illness which clogs the lungs with excess thick and sticky mucus. "From early childhood he was weak, prone to chest infections, wheezing, coughing," Cichy said. Records show that as an adult weighing 40 kilograms (about 88 pounds) at a height of 1.70 metres (five foot seven inches), Chopin was chronically underweight another telltale symptom of cystic fibrosis. Cichy also pointed out that despite a passionate romance with flamboyant French writer George Sand, Chopin had no known children, suggesting infertility another telling clue. And few cystic fibrosis sufferers live past 40. "If we can prove Chopin suffered from cystic fibrosis, it would be a huge inspiration for our patients, especially children, to know they can accomplish a great deal like he did," Cichy told AFP. Grzegorz Michalski, director of Poland's National Fryderyk Chopin Institute, said the last known time the heart was examined was just after the end of World War II in 1945. It showed the heart was "perfectly preserved" in the hermetically-sealed crystal urn that was filled with an alcoholic liquid presumed to be cognac. "Records show it is in perfect condition, so to tamper with it risks destroying it," Michalski said, adding that while one of two of Chopin's living descendents favours DNA testing, the other is staunchly opposed. No one has yet asked the Friars of St Vincent de Paul at the Holy Cross church whether they'd agree to the test. "I can't comment on the matter in any way because, until now, no one has contacted us with either a question or any kind of proposal to test Chopin's heart," said senior priest Father Marek Bialkowski. Iwona Radziszewska, spokesman for the culture ministry, said "an appropriate decision" would be taken upon review of a series of studies now underway. Climbing the steps of the cream-colored Holy Cross church on her way to see the pillar that holds Chopin's heart, Swedish tourist Lisa Bondeling, 24, was perplexed by the idea of running DNA tests on it. "It's best just to leave it," she said. "What is there to find out, really? He's dead." Another visitor, Angela, 21, a student from Shanghai, agreed: "It was his wish to bury his heart in his homeland, so it's better not disturb him. He's already dead. Why don't we just let him rest in peace." As a Polish emigre in his father's native France after an 1830-31 uprising of Polish insurgents against the 1795 partition of Poland by Russia, Prussia and Austria, Chopin refused to take a Russian passport. Thus he was never able to set foot on his native soil after the doomed insurrection. "The uprising was a drama that ruptured Chopin's life," said Michalski, explaining the musician's desperate homesickness and his dreams of Polish independence. Described by 19th century German composer Robert Schumann as "cannons hidden among blossoms," Chopin's music was and remains a symbol of Poland's long struggle for freedom. Nazi Germany banned Chopin's music for that very reason. But Michalski recalled that it was a German general, Erich von dem Bach, who saved the heart from oblivion amid a relentless Nazi bombing campaign during the 1944 uprising by Polish partisans in what then was occupied Warsaw.