16p13.3 microduplication syndrome is a rare chromosomal anomaly syndrome resulting from a partial duplication of the short arm of chromosome 16 and manifesting with a variable phenotype which is mostly characterized by: mild to moderate intellectual deficit and developmental delay (particularly speech), normal growth, short, proximally implanted thumbs and other hand and feet malformations (such as camptodactyly, syndactyly, club feet), mild arthrogryposis and characteristic facies (upslanting, narrow palpebral fissures, hypertelorism, mid face hypoplasia, bulbous nasal tip and low set ears). Other reported manifestations include cryptorchidism, inguinal hernia and behavioral problems. The disease is Monarch Disease Ontology term MONDO_0013273 (chromosome 16p13.3 duplication syndrome). Also known as: 16p13.3 microduplication syndrome, chromosome 16p13.3 duplication syndrome, isolated cases, distal duplication 16p, distal trisomy 16p, dup(16)(p13.3), telomeric duplication 16p, trisomy 16pter.