Rare somatic manifestations of telomere biology disorders.

Telomere biology disorders (TBDs) are characterized by numerous somatic features across multiple organ systems, which contribute significantly to the morbidity and mortality of these conditions. In many cases, rare somatic manifestations may represent the earliest symptoms of a TBD and the first presentation to subspecialty care, and thus a high index of suspicion is necessary for timely diagnosis. Hoyeraal-Hriedarsson Syndrome, Revesz Syndrome, and Coats Plus Syndrome represent severe phenotypes with characteristic somatic features often diagnosed in early childhood. However, all patients with TBDs may exhibit these varied symptoms throughout the lifespan. Of note, patients continue to experience disease-related complications across multiple organ systems even after hematopoietic stem cell transplant, reinforcing the need for lifelong multidisciplinary care for patients with TBDs. In this chapter, we describe neurological, immunologic, gastrointestinal, ophthalmic, and endocrinologic manifestations of TBDs, among others.