49,XYYYY syndrome

Get in touch with RARE Concierge.

Contact RARE Concierge

A rare Y chromosome number anomaly with a variable phenotype mainly characterized by moderate to severe intellectual disability speech delay hypotonia and mild dysmorphic features including facial asymmetry hypertelorism bilateral low set ‘lop’ ears and micrognatia. Skeletal abnormalities (such as skull deformities radioulnar synostosis elbow flexion clinodactyly brachydactyly) and behavourial problems have also been associated with this condition. Genitalia are normal at birth although hypogonadism and azoospermia has been reported in adults.

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 October 2024

Newly diagnosed with
49,XYYYY syndrome?

Our RARE Concierge Services Guides are available to assist you by providing information, resources and connections as you navigate your rare disease journey.

Get Concierge Help

Advocacy Organizations

Don't see your organization here. Let us know here.

Clinical Trials

For a list of clinical trials in this disease area, please click here.