One group of conditions involving the infant population is congenital anomalies. Several terms are important to remember when discussing congenital anomalies. A malformation is a congenital anomaly due to an intrinsic defect in development. A disruption occurs when a normally developing organ is secondarily damaged by another process. For example, in amniotic band syndrome, a fragment of the amniotic membrane wraps around a portion of the body and damages or amputates it. A deformation is an abnormal development of an organ due to an extrinsic process. A sequence is a collection of several anomalies, all of which are due to one malformation, disruption, or deformation. For example, Potter sequence is due to oligohydramnios and includes flat facies, small chest, hypoplastic lungs, club foot (talipes equinovarus), and nodules in the amniotic sac. Finally, a syndrome is a group of related anomalies. Common congenital anomalies include clubfoot, patent ductus arteriosus, ventricular septal defect, and cleft lip or cleft palate. Although most congenital anomalies are diagnosed during infancy, they are present and can cause complications into adulthood.