Telomere length of both parents contributes to heritable POT1 cancer-predisposition syndrome.

POT1

Germline POT1 variants causing aberrant telomere elongation, with preferential elongation of the shortest telomeres inherited from both parents

Germline POT1 variants promote oncogenesis by enabling aberrant telomere elongation; whether these long telomeres are transmitted to offspring remained unclear. Using nanopore sequencing that resolves telomere length by haplotype, the authors studied telomere inheritance in families carrying POT1 variants. Offspring preferentially inherit their longest telomeres from the carrier parent and their shortest telomeres from the non-carrier parent; comparison of carrier and non-carrier siblings shows that in carriers, telomeres from both parents are elongated, especially the shortest ones. The authors propose a mechanism of genetic anticipation in which POT1 variants progressively deplete, from the carrier germline, the short telomeres capable of enforcing tumour suppression.

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

An elegant mechanistic study, made possible by long-read sequencing resolving telomere length by haplotype, but the abstract gives neither the number of families nor a direct link with cancer occurrence. If the anticipation hypothesis were confirmed, the contribution of the non-carrier parent's telomeres would become a parameter to consider, currently absent from genetic counselling. As it stands, no change in carrier management.

Analysis by Dr Thibaut Benquey