Brachydactyly is an inherited condition, which makes genetics the main cause. If you have shortened fingers or toes, other members of your family most likely also have the condition. It is an autosomal dominant condition, which means you only need one parent with the gene to inherit the condition.

How common are stubby thumbs?

It's not so unusual, though. Up to 4 percent of the population is estimated to have stubby thumbs.

Why are my thumbs stubby?

More commonly referred to as "clubbed thumbs" and often comically called "toe thumbs" (delightful!), brachydactyly type D is an inherited condition in which "the end bones of the thumbs are shortened but all the fingers are normal," according to HealthLine.