Distal trisomy 5q is a rare chromosomal anomaly syndrome, resulting from a partial duplication of the long arm of chromosome 5, characterized by short stature, moderate intellectual disability, and craniofacial dysmorphism (microcephaly, flat facies, large, low-set dysplastic ears, down-slanted, almond-shaped palpebral fissures, hypertelorism, epicanthal folds, small nose, long philtrum, small mouth with thin upper lip, and micrognathia). Patients also frequently present speech and cognitive delay, cardiac (ventriculomegaly, ventricular septum defect) and skeletal abnormalities (craniosynostosis, radial agenesis, ulnar hypoplasia, brachydactyly) and genital malformations (hypospadias, cryptorchidism).

Distance between nasal base and midline upper lip vermilion border more than 2 SD above the mean. Alternatively, an apparently increased distance between nasal base and midline upper lip vermilion border.