BOSTON — A freezer failure at the world’s largest brain bank has damaged nearly 150 brains, including one-third of those used in autism research.

The Harvard Brain Tissue Resource Center is housed at McLean Hospital in Belmont, Mass., and provides tissue for the study of neurological disorders. On May 31, a technician at the hospital discovered that the freezer had failed when he went to retrieve a sample.

Of the thawed brains, 54 were designated for autism research, and 93 were for research on psychiatric conditions and neurodegenerative diseases like Parkinson’s and Huntington’s.

The freezer was one of 24 used by the brain bank, which stores about 3,000 brains. Research on autism will probably be most affected, potentially delaying discoveries in the field for years.