48,XYYY syndrome
MONDO:0020469
48,XYYY syndrome is 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 stenosis and clinodactyly have also been associated. Boys generally present normal genitalia, while hypogonadism and infertility is frequently reported in adult males.
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Directly mapped studies only · unique clinical trialsCurrent registry observations. Phase counts may overlap. Study start dates are not registry registration dates. Investigational interventions are not approved-treatment recommendations.
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XYYY syndrome
XYYY syndrome, also known as 48,XYYY, is a chromosomal disorder in which a male has two extra copies of the Y chromosome. The syndrome is exceptionally rare, with only twelve recorded cases. The presentation of the syndrome is heterogeneous, but appears to be more severe than its counterpart XYY syndrome. Common traits include borderline to mild intellectual disability, infertility, radioulnar synostosis (the fusion of the long bones in the forearm), and in some cases tall stature.
Background only. Canonical identity remains MONDO; clinical-trial relationships come from ClinicalTrials.gov.Drugs being studied
Disease identity and terminology: MONDO. Trial relationships: ClinicalTrials.gov.