Hoyeraal-Hreidarsson syndrome

Hoyeraal-Hreidarsson syndrome is a very rare multisystem X-linked recessive disorder characterized by excessively short telomeres, and it is considered a severe form of dyskeratosis congenita. Because it is X-linked, it primarily affects males. Patients typically present in early childhood with cerebellar hypoplasia, immunodeficiency, progressive bone marrow failure and intrauterine growth restriction. The primary cause of death is bone marrow failure, although deaths from cancer and from pulmonary fibrosis are also significant. The entry records what the source lead supports: a telomere disorder in which short telomeres, an inherited X-linked pattern and failure of the bone marrow and immune system define the clinical picture from early childhood.