A Case Series of Variant Telomere Biology Disorders in Unrelated Families From Atlantic Canada.

variant telomere biology disorders (TBDs) are a rare, heterogenous group of disorders that arise from germline variants in , a gene that encodes for the RNA component of telomerase. Variants in lead to accelerated telomere attrition and can manifest as many different phenotypes. In this case series, we aimed to add to the literature describing variant TBDs by reporting cases from two unrelated families from Atlantic Canada. The first case, a previously described germline variant, n.107G>T (NR_001566.1), was identified in a young woman with myelodysplastic syndrome (MDS) and found to segregate with cytopenias in the family. This case represents a unique phenotypic presentation: this variant has not previously been described in patients with MDS and adds important segregation data to the literature. The second case, a novel n.437T>G variant, was identified in a patient with both aplastic anemia and pulmonary fibrosis manifesting in his early 30s. We report these novel cases of germline variants in order to help clinicians recognize TBDs, as well as to add important supporting information for the pathogenicity of these variants.