Autosomal Recessive

 "Autosomal recessive" refers to a specific pattern of inheritance.   If a disorder is inherited in an autosomal recessive manner, it means an individual has to inherit two mutations of the disorder, one from each parent, in order to be affected by it.

A person who has only one recessive gene is said to be a "carrier" for the trait or disease, but they do not have any health problems from "carrying" one copy of the gene. However, they could have a child affected with this disorder if their partner also carries a mutation for that same condition.  This is  the case with genetic disorders like SMA (Spinal Muscular Atrophy), Tay Sachs Disease, Cystic Fibrosis and Sickle Cell Anemia.

Most people do not know they carry a recessive gene for a disease until they have a child with the disease. Most banks screen for Tay Sachs (primarily on Jewish donors) and Cystic Fibrosis.  Others may test for Sickle Cell Anemia but the only bank currently testing for SMA is California Cryobank.