MONTECITO, Calif. — Even as she mourned the death of her 29-year-old husband from a rare genetic disorder, Sarah Robertson was comforted by knowing that six vials of his sperm were safely stored at the Reproductive Fertility Center — in Tank B, Canister 5, Cane G, Position 6, Color Blue — waiting until she was ready to have the baby they had both longed for.

But 10 years later, when she was ready to use the sperm from her husband, Aaron, she got devastating news. All six vials were missing.

“I’d been completely focused on having something of Aaron’s live on, and now there was nothing,” said Ms. Robertson in an interview at her in-laws’ home in Montecito.

Now she and her in-laws are suing the Los Angeles clinic, and its owner, Dr. Peyman Saadat, accusing them of negligence, fraud, breach of contract and intentional infliction of emotional distress. The suit, filed in May, also says the clinic misappropriated Mr. Robertson’s sperm — which had a 50 percent chance of carrying Marfan syndrome, the disorder that killed him — and used it to supply other patients who would not know to undergo testing to ensure their babies did not inherit the disorder.