Trisomy 1q is a rare chromosomal anomaly syndrome, resulting from the partial duplication of the long arm of chromosome 1, with a highly variable phenotype principally characterized by intellectual disability, short stature, craniofacial dysmorphism (incl. macro/microcephaly, prominent forehead, posteriorly rotated, low-set ears, abnormal palpebral fissures, microphthalmia, broad, flat nasal bridge, high-arched palate, micro/retrognathia), cardiac defects and urogenital anomalies. Patients may also present cerebral (e.g. ventriculomegaly) and gastrointestinal malformations, as well as dystonic tremor and recurrent respiratory tract infections. The disease is Monarch Disease Ontology entry MONDO_0016847 (trisomy 1q). Also known as: Duplication 1q, trisomy type 1q.