Inherited POT1 Mutations That Lengthen Telomeres Tied to Eightfold Higher Lymphoma Risk

Overview

• Johns Hopkins researchers reported Thursday in Blood that inherited POT1 loss-of-function keeps chromosome end caps, called telomeres, unusually long and raises lymphoma risk.
• Analysis of 210 adults with POT1 variants in the UK Biobank found about an eightfold higher risk of lymphoma, with an estimated 45% developing a lymphoid cancer by age 80.
• In 24 affected families, most blood cancers arose from lymphocytes, spanning childhood leukemia, multiple lymphomas, and adult chronic lymphocytic leukemia.
• Lymphocytes from carriers did not show the usual telomere shortening with age, which lets long‑lived cells retain cancer-linked mutations and form expanded clones that became common after 60.
• Clinical guidance is unsettled, and the authors recommend telomere-length testing only for POT1 variants of uncertain significance as research works to define surveillance.