This morning Sequoia Capital sent investors an unwelcome Monday morning note. That’s an understatement. This is a bombshell.

Mike Moritz disclosed to the firm’s limited partners that he has “a rare medical condition which can be managed but is incurable.” As a result, he’ll be stepping back as managing director of the firm. A Sequoia spokesperson emphasized that this is more about Moritz’s role shifting at the firm than anything else. He’ll be spending less time on the day-to-day running and management of Sequoia, and more time with entrepreneurs. He will be taking on new deals and board seats. And in the letter below, the 57-year-old Moritz notes that he’s never felt healthier.

Moritz may not have the name recognition of Steve Jobs, but for the startup world this is every bit the bombshell as when we first heard about Jobs’ ailing health. Moritz has long been one of the most powerful investors in the Valley — loved and feared, much like Jobs.

He is a commanding figure that most people can’t imagine the Valley without. We wish him continued good health and all the best defying the odds.

From the letter:

We have always tried to be straightforward with you and, in that spirt, I need to share something. Unfortunately, I have been diagnosed with a rare medical condition which can be managed but is incurable. I’ve been told that in the next five to ten years the quality of my life is quite likely to decline. Right now I feel fitter than ever and I hope that I’ll be one of the lucky ones who can live a full life and defy the statisticians. But there is no way of predicting this with certainty and thus for me, life has assumed a different meaning and I am making some adjustments.

I am going to extract myself from the daily management of Sequoia Capital, a task that has consumed a large part of my time for the past sixteen years. I will become Chairman of Sequoia Capital and will be deeply involved with nurturing the fresh investments, ideas and relationships that can be of significant long-term benefit for all of us. I will also work very closely with some of our younger and newer members, will continue my role as Managing Member of existing funds and maintain all my current company responsibilities. I will use twelve to fourteen weeks – sprinkled throughout the course of each year – for various pursuits, diversions and trivial indulgences.

Nothing about this should cause much of a change because everything that has been achieved at Sequoia Capital has resulted from the teamwork and contribution of many people. Our overall business is in the best shape it has ever been and we are better positioned than at any time in our forty year history. Doug Leone will assume full responsibility for coordinating the business we have gradually developed over the past couple of decades and almost everything else remains entirely the same.

Thanks for your support,

Michael Moritz