Hepatic manifestations of telomere biology disorders

A 51-year-old Caucasian male was referred for evaluation of variceal bleeding. Laboratory tests were remarkable for mild thrombocytopenia and moderate alkaline phosphatase elevation. Synthetic liver function was well preserved. Abdominal computed tomography scan revealed moderate splenomegaly, gastric varices, and normal hepatic contour. A transjugular liver biopsy was performed revealing findings of nodular regenerative hyperplasia with no significant fibrosis or necroinflammatory activity. Hepatic venous pressure gradient was elevated at 31 mmHg, consistent with clinically significant portal hypertension. The clinical course was complicated by refractory gastric variceal bleeding requiring a surgical portosystemic shunt. Approximately seven years after the initial presentation, the patient developed progressive dyspnoea and a diagnosis of idiopathic pulmonary fibrosis was made. Contrast-enhanced echocardiogram was not suggestive of hepatopulmonary syndrome or portopulmonary hypertension. Given this new diagnosis a telomere biology disorder was suspected. A flow-fluorescence in situ hybridisation analysis for telomere length assessment revealed telomere lengths below the first percentile in both lymphocytes and granulocytes. Next generation sequencing analysis identified a heterozygous mutation involving the hTERT gene (Histidine983Threonine). The lung disease unfortunately progressed in the subsequent two years, leading to the patient's death nine years after his initial presentation with portal hypertension. During those nine years two brothers also developed idiopathic pulmonary fibrosis. The questions that arise from this case include: I. What are telomere biology disorders?II. What are the hepatic manifestations of telomere biology disorders?III. How are telomere biology disorders diagnosed?IV. Are there any potential therapeutic options for telomere biology disorders?