Although people with 49,XXXXY syndrome are sometimes referred to as having a variant of Klinefelter syndrome, the features of these are generally distinct and 49,XXXXY syndrome is more severe.
You can read more about the features of 49,XXXXY syndrome in a fact sheet provided by Unique. The information in this fact sheet comes from both the medical literature and reports of some members of Unique who took part in a survey in 2004.
The Human Phenotype Ontology (HPO) provides the following list of features that have been reported in people with this condition. Much of the information in the HPO comes from Orphanet, a European rare disease database. If available, the list includes a rough estimate of how common a feature is (its frequency). Frequencies are based on a specific study and may not be representative of all studies. You can use the MedlinePlus Medical Dictionary for definitions of the terms below.
|Signs and Symptoms||Approximate number of patients (when available)|
|Abnormality of dental enamel||90%|
|Functional abnormality of male internal genitalia||90%|
|Hypoplasia of penis||90%|
|Neurological speech impairment||90%|
|Abnormality of epiphysis morphology||50%|
|Abnormality of the hip bone||50%|
|Abnormality of the shoulder||50%|
|Attention deficit hyperactivity disorder||50%|
|Clinodactyly of the 5th finger||50%|
|Delayed eruption of teeth||50%|
|Multicystic kidney dysplasia||50%|
|Recurrent respiratory infections||50%|
|Upslanted palpebral fissure||50%|
|Abnormality of calvarial morphology||7.5%|
|Abnormality of the mandible||7.5%|
|Aplasia/Hypoplasia of the corpus callosum||7.5%|
|Depressed nasal bridge||7.5%|
|Type II diabetes mellitus||7.5%|
Nonprofit support and advocacy groups bring together patients, families, medical professionals, and researchers. These groups often raise awareness, provide support, and develop patient-centered information. Many are the driving force behind research for better treatments and possible cures. They can direct people to research, resources, and services. Many groups also have experts who serve as medical advisors. Visit their website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.
These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.
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My son is now 13 months old and has XXXXY syndrome. Is there a chance that another child can also get this syndrome? And is there any treatment in any part of the world to cure this syndrome? See answer
My 7 year old son was recently diagnosed with 49,XXXXY. I am looking for information on a specialist and any other information that can be provided. See answer