Clinical features underlying TBDs and possible diagnostic evaluation results. Telomere length testing should be considered for all patients with the indications shown. All patients with BMF or head/neck squamous cell carcinoma (HNSCC) should also have chromosome breakage testing of blood (and skin, if indicated) to rule out Fanconi anemia. Family history may be helpful if it is present, but many patients do not have affected relatives due to variable disease penetrance, expressivity, and/or genetic anticipation.

HNSCC, head and neck squamous cell carcinoma; IUGR, intrauterine growth restriction.