Autosomal recessive inheritance is a way that a trait, disorder, or disease can be passed down through families. It means that two copies of an abnormal gene must be present in order for the disease or trait to develop. Genes come in pairs, and one gene in each pair comes from the mother, and the other gene comes from the father. Recessive inheritance means both genes in a pair must be abnormal to cause disease. People with only one defective gene in the pair are called carriers. These people are most often not affected with the condition, but they can pass the abnormal gene to their children. If both parents are carriers of the same autosomal recessive gene, their child has a 25% chance of inheriting the abnormal gene from both parents and developing the disease, a 50% chance of inheriting one abnormal gene and becoming a carrier, and a 25% chance of inheriting two normal genes. Autosomal recessive inheritance can be traced through a family to determine which individuals are carriers and which individuals are likely to become impacted.