How Common Is It?
An STPC is not extremely rare, but it is uncommon.
Around 3–4% of people have a single transverse palmar crease on at least one hand.
Having it on both hands (bilateral STPC) is much less common, occurring in roughly 1% of the population, although estimates vary among different populations and studies.
Many people with this trait discover it only after someone points it out.
Does It Mean Something Is Wrong?
For most people, no.
A single transverse palmar crease is often simply a natural variation of human anatomy.
Many healthy children and adults have one on one or both hands and never experience any problems because of it.
Why Do Doctors Sometimes Mention It?
Doctors may note an STPC during a newborn examination because it can sometimes occur alongside certain genetic or developmental conditions.
However, the crease by itself does not diagnose any medical condition.
Healthcare providers look at the whole person—including growth, development, medical history, physical examination, and any other findings—not just one line on the palm.
