Every gene in our carrier screen

What the list means

Each gene on this list is linked to a recessive condition. A recessive condition usually appears only when a child inherits a changed copy of the same gene from both parents.

A carrier has one changed copy and usually no symptoms. If both parents carry a change in the same gene, each child has a one-in-four chance of having the condition.

The list includes the conditions most carrier screens test for: cystic fibrosis (CFTR), spinal muscular atrophy (SMN1), fragile X syndrome (FMR1), sickle cell disease and beta thalassemia (HBB), alpha thalassemia (HBA1, HBA2) and Tay-Sachs disease (HEXA). For spinal muscular atrophy, we count the copies of SMN1. For fragile X, we measure the repeat in FMR1.

Some genes on the list, such as BRCA2 or APOE, are better known for the effect of one changed copy. They are on this list for the condition that two changed copies cause. For BRCA2, that is a form of Fanconi anemia. If you have one changed copy of BRCA2, your report shows it in a separate section, with the genes that matter for your own health.

Genes on the X chromosome follow a different pattern. A mother who carries a change in one of them can pass the condition to a son.

The list combines two expert databases of genes and diseases (GenCC and ClinGen) with the published commercial carrier panels. Your report names the genes where something relevant to you was found. How well each gene was sequenced varies from sample to sample. Your report states it for yours.