1. Telomere-lengthening germline variants predispose to a syndromic papillary thyroid cancer subtype.
- Author
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DeBoy, Emily A., Nicosia, Anna M., Liyanarachchi, Sandya, Iyer, Sheila S., Shah, Manisha H., Ringel, Matthew D., Brock, Pamela, and Armanios, Mary
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THYROID cancer , *GERM cells , *TELOMERES , *GENETIC variation , *BONE lengthening (Orthopedics) , *LONGEVITY , *MELANOMA , *BRAF genes - Abstract
Papillary thyroid cancer (PTC) is the most common endocrine malignancy. 10% to 15% of individuals show familial clustering with three or more affected members, but the factors underlying this risk are unknown. In a group of recently studied individuals with POT1 pathogenic variants and ultra-long telomere length, PTC was the second most common solid tumor. We tested whether variants in POT1 and four other telomere-maintenance genes associated with familial cancer underlie PTC susceptibility. Among 470 individuals, we identified pathogenic or likely pathogenic variants in three genes encoding telomere-binding proteins: POT1 , TINF2 , and ACD. They were found in 4.5% and 1.5% of familial and unselected cases, respectively. Individuals harboring these variants had ultra-long telomere length, and 15 of 18 (83%) developed other cancers, of which melanoma, lymphoma, and sarcoma were most common. Among individuals with PTC and melanoma, 22% carried a deleterious germline variant, suggesting that a long telomere syndrome might be clinically recognizable. Successive generations had longer telomere length than their parents and, at times, developed more cancers at younger ages. Tumor sequencing identified a single oncogenic driver, BRAF p.Val600Glu, in 10 of 10 tumors studied, but no telomere-maintenance mechanism, including at the TERT promoter. These data identify a syndromic subset of PTCs with locus heterogeneity and telomere lengthening as a convergent mechanism. They suggest these germline variants lower the threshold to cancer by obviating the need for an acquired telomere-maintenance mechanism in addition to sustaining the longevity of oncogenic mutations. DeBoy et al. identify telomere-lengthening variants in genes encoding three telomere-binding proteins as monogenic risk factors for papillary thyroid cancers, the most common of endocrine malignancies. Eighty-three percent of individuals had second cancers, of which melanoma, sarcoma, and lymphoid malignancies were most common. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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