Clinical and surveillance outcomes of the TP53 c.1000G > C (p.Gly334Arg) variant.

Germline TP53 p.Gly334Arg missense variant, an Ashkenazi Jewish founder allele associated with a later-onset, apparently lower-penetrance cancer phenotype.

The TP53 c.1000G>C (p.Gly334Arg) variant, a founder allele in the Ashkenazi Jewish population, has been reported as a lower-penetrance, later-onset predisposition allele, but its classification and the optimal surveillance of carriers remain debated. This retrospective descriptive study analysed 18 heterozygous carriers from five families, all of Ashkenazi Jewish ancestry, followed in two Israeli hereditary cancer clinics between 2021 and 2025. Seven of 18 carriers (39%) had a personal history of malignancy, breast cancer being the most common (four women, all diagnosed after age 50, hormone receptor-positive where pathology was available); no paediatric malignancies were observed and no carrier met classic or Chompret criteria for Li-Fraumeni syndrome. Ten carriers underwent serial whole-body MRI surveillance, totalling 36 examinations (mean 3.6 per patient): no malignancy was detected, but nine abnormal findings arose (0.25 per scan), all false positives, one leading to invasive procedures. The authors conclude that current data are insufficient to modify existing TP53 surveillance protocols.

Synthesis written by Geno'X. For the full original abstract, please refer to the source publication.

These real-world data illustrate the cost of applying classic Li-Fraumeni surveillance to an attenuated-penetrance TP53 allele: no cancer detected, one false positive every four scans, and a cascade of invasive procedures. They are not sufficient — as the authors themselves state — to change protocols, since 18 carriers and short follow-up preclude any conclusion on penetrance. The topic remains central to genetic counselling: what is emerging is surveillance stratified by the specific TP53 allele rather than by the gene alone.

Analysis by Dr Thibaut Benquey