A rare Y chromosome number anomaly that affects only males and is characterized by mild-moderate developmental delay (especially speech) normal to mild intellectual disability large irregular teeth with poor enamel tall stature and acne. Radioulnar synostosis and clinodactyly have also been associated. Boys generally present normal genitalia while hypogonadism and infertility is frequently reported in adult males.
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 June 2026
Newly diagnosed with
48,XYYY syndrome?
Our RARE Concierge Services Guides are available to assist you by providing information, resources and connections as you navigate your rare disease journey.
Advocacy Organizations
PPP2CA Pathways
PPP2CA Pathways connects families, shares strength, and supports the research community in the search for answers to Houge-Janssens Syndrome type 3.
Rare Chromosome Disorder Support Group – Unique
Through sharing knowledge and lived experience, Unique helps families and professionals navigate the world of chromosome and gene disorders
ReNU2 United
ReNU2 United fosters collaboration, supports families, raises awareness, and advances research into RNU2-2-related neurodevelopmental disease.
Uganda Alliance of Patients Organization
Supporting patients to access quality, safe and patient-centered healthcare services.
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Clinical Trials
For a list of clinical trials in this disease area, please click here.