A deviation from a normal occurrence or a pattern is called an anomaly. It is usually something that occurs at birth. It might be a structural aberration, an irregularity, or a congenital defect. It might also be a genetic mutation or genetic disorders that lead to certain diseases like type 1 diabetes. Some anomalies include Pelger’s nuclear anomaly, Ebstein’s anomaly, Cri du chat syndrome, and myoclonic epilepsy.