Synonyms: Progressive pancytopenia-immunodeficiency-cerebellar hypoplasia syndrome
A rare X-linked syndromic intellectual disability considered to be a severe variant of dyskeratosis congenita characterized by intrauterine growth retardation microcephaly cerebellar hypoplasia progressive combined immune deficiency and aplastic anemia.
Data from Orphanet are used to provide information on a disease's name, synonym(s), and overview. Reference: Access aggregated data from Orphanet at Orphadata. Orphadata: Free access data from Orphanet. © INSERM 1999. Available on http://www.orphadata.org. Data version August 2026
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Hoyeraal-Hreidarsson syndrome?
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Advocacy Organizations
Immune Deficiency Foundation
To improve the diagnosis, treatment and quality of life of people affected by primary immunodeficiency.
Immunocompromised Association
Immunocompromised Association promotes awareness, education, and support for immunocompromised individuals to reduce their inherent health risks in the community.
No somos invisibles IDP – Perú
Nuestra misión es visibilizar, representar y defender los derechos de las personas con Inmunodeficiencias Primarias (IDP), promoviendo el acceso oportuno a diagnóstico, tratamiento y atención integral, fortaleciendo a pacientes y familias y construyendo una sociedad más informada, inclusiva y solidaria.
ReNU2 Foundation
ReNU2 Foundation supports families affected by RNU2-2-related neurodevelopmental disease. We foster collaboration, raise awareness, and advance research—pursuing a world where every family has testing, informed care, community, and treatment.
The AIP BIPOC Network
The AIP BIPOC Network is a 501(c)(3) nonprofit advancing equity in autoimmune and chronic illness care. We support BIPOC and underserved communities through a dual framework: systemic change via Access, Inclusion, and Prevention, and individual empowerment through the Autoimmune Protocol.
Uganda Alliance of Patients Organization
Supporting patients to access quality, safe and patient-centered healthcare services.
Ukrainian Association of Pediatric Immunology
Development of pediatric and clinical immunology in Ukraine. Raising awareness of inborn errors of immunity in Ukraine and rare immune diseases; Advocacy campaigns supporting patients with rare immune diseases and their treatment plans; Scientific research; Sharing knowledge about immunoprophylaxis; Advocacy campaigns supporting immunoprophylaxis.
accessia health
Accessia Health, a national charitable patient assistance organization, is dedicated to eliminating healthcare barriers for people with rare or chronic health conditions. Comprehensive services include personalized case management, financial assistance, education, and legal aid support. Our flexible funding model goes beyond copays, allowing individuals to pay for other essential medical expenses
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Clinical Trials
For a list of clinical trials in this disease area, please click here.