Japan's national health insurance will cover a gene therapy drug for a rare childhood genetic disorder that costs ¥167 million per treatment, making it the most expensive medication funded by the public system, government officials said Wednesday.

An advisory panel to the health minister approved provision of Swiss pharmaceutical giant Novartis AG's drug Zolgensma for spinal muscular atrophy patients under the age of 2 starting as early as May 20, the officials said.

The drug, which costs over ¥200 million in the United States, is known as the world's most expensive medication.