Book ~ "Find You First" (2021) Linwood Barclay

From Goodreads ~ Tech millionaire Miles Cookson has more money than he can ever spend, and everything he could dream of - except time. He has recently been diagnosed with a terminal illness and there is a fifty percent chance that it can be passed on to the next generation. For Miles, this means taking a long hard look at his past.

Two decades ago, a young, struggling Miles was a sperm donor. Somewhere out there, he has kids - nine of them. And they might be about to inherit both the good and the bad from him - maybe his fortune or maybe something much worse.

As Miles begins to search for the children he’s never known, aspiring film documentarian Chloe Swanson embarks on a quest to find her biological father, armed with the knowledge that twenty-two years ago, her mother used a New York sperm bank to become pregnant.

When Miles and Chloe eventually connect, their excitement at finding each other is overshadowed by a series of mysterious and terrifying events. One by one, Miles’s other potential heirs are vanishing - every trace of them wiped, like they never existed at all.

Who is the vicious killer - another heir methodically erasing rivals? Or is something even more sinister going on?

It’s a deadly race against time.

Miles is a tech millionaire who just found out he has Huntington's disease.  There's no cure and he's going to get progressively worse and there's no way to know how fast he will decline.  He's not married nor has he children but it is a hereditary disease.  More than 20 years ago, in need of money, he went to a sperm bank so there is a chance that he may indeed have children.  He discovers his sperm was used to produce nine children.  He feels it's his duty to let them know they may be carrying the gene for the disease and he wants to ensure they are taken care of monetarily whether they do or not.  So he begins his search to contact these nine people.

Chloe's mother had used a sperm donor many years ago which has prompted Chloe's interest to find out more about her family and also see if she can discover who her father is.  She does a DNA test and discovers she has a half brother, Todd.  She and Todd connect and are happy to have found each other.  Around this time, Miles contacts Chloe because she is on his list and is the closest geographically.  As they are getting to know each other, the others on the list start disappearing which is puzzling.  Is it a coincidence or does it have anything to do with being one on Miles' list?

I've read many books by this author and I liked this one.  The story had lots of twists and turns.  I found it especially interesting because I've done a couple DNA tests and have discovered cousins I didn't know about.  It is written in third person perspective from many points of view, depending on where the action was.  As a head's up, there is swearing.