Nucleoside Therapy in Patients With Telomere Biology Disorders

Inclusion Criteria10

• Age ≥ 1 year and ≤ 70 years
• Karnofsky performance status ≥ 50 for participants ≥16 years of age and Lansky performance status ≥ 50 for participants \<16 years of age
• Diagnosis requirement. Participants must meet at least one of the following requirements for a diagnosis of a telomere biology disorder:
• Age-adjusted mean telomere length \< 1%ile in peripheral blood lymphocytes by flow cytometry-fluorescence in situ hybridization (flow-FISH), as reported by a Clinical Laboratory Improvement Amendments (CLIA)-approved laboratory
• OR
• Pathogenic or likely pathogenic variant(s) in one of the follow telomere biology associated genes: DKC1, TERC, TERT, NOP10, NHP2, WRAP53/TCAB1, TINF2, CTC1, RTEL1, ACD, PARN, NAF1, STN1, ZCCHC8, POT1, RPA1, DCLRE1B, TYMS, as reported by a CLIA-approved laboratory.
• Participants must exhibit at least one active clinical manifestation associated with a telomere biology disorder, in the judgment of the PI, which includes but is not limited to the following: one or more peripheral blood cytopenias, bone marrow hypocellular for age, pulmonary abnormalities, liver abnormalities, gastrointestinal bleeding, immunodeficiency or immune dysregulation, ophthalmologic abnormalities, or neurologic abnormalities.
• Participants must be able to take enteral liquids by mouth or enteral feeding tube.
• Female participants who are sexually active and could become pregnant must use two effective methods of contraception, at least one of which must be considered a highly effective method.
• Participants (or parent/legally authorized representative for minors) must demonstrate the ability to understand and willingness to provide informed consent, which will be documented using an institutionally approved informed consent procedure.