tetrasomy 21
MONDO:0019864
Tetrasomy 21 is an extremely rare autosomal anomaly resulting from the presence of 4 copies of chromosome 21, characterized by features of trisomy 21 including developmental delay/intellectual disability, muscular hypotonia, short neck with redundant skin, brachycephaly, microcephaly, flat face, epicanthus, upslanted palpebral fissures, small ears, protruding tongue, single transverse palmar crease, brachydactyly, hypoplastic iliac wings, together with additional features such as prematurity, intrauterine growth retardation, high and broad forehead, hypertelorism. Haematological malignancies are also associated and may occur earlier than in trisomy 21.
Research intelligence
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.
Medications under investigation
Verified disease and drug mappings that co-occur within the same study; not evidence of effectiveness.
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tetrasomy 21
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.