It is an issue that’s received national attention this year — sparked in part by the New Republic’s “Silicon's Valley's Brutal Ageism” story. Now Twitter is facing charges that it fired a 57-year-old employee based on his age and medical problems.

As SF Weekly reports, former Twitter employee Peter H. Taylor filed a lawsuit last week that claims the company terminated him “without warning, without notice, without explanation.” The complaint states that a "substantially younger" supervisor “made at least one critical remark” about his age.

In addition, Taylor was diagnosed with kidney stones in April 2013, which required surgery and multiple doctor visits. Taylor says Twitter denied his request to have employees pitch in and help with his responsibilities. He was fired on September 23, 2013, a month after undergoing surgery, according to the suit, and was replaced by employees in their 20s and 30s

During his two and a half years at the company, the complaint states that Taylor helped Twitter expand its data centers and saved them “over 10 million dollars.” He received 20,000 Restricted Stock Units as a performance bonus.

Taylor is seeking damages incurred, which exceed $25,000, plus reimbursement of his lawyers' fees.

A Twitter spokesperson told SF Weekly the case is without merit: “We will vigorously defend ourselves against it."

[SF Weekly]