Single-gene disorders are caused by changes in a single gene. If you have a family history of an inherited disorder that is caused by an alteration in a single gene (such as cystic fibrosis), you may be offered a specific test, called a single-gene test, just for this. You may already have spoken to someone at the genetics service, or your midwife or obstetrician can refer you to the genetics service if you tell them you have a family history of an inherited disorder. The genetics team will discuss the options with you and explain the risks. Options may include invasive tests, such as chorionic villus sampling (CVS) or amniocentesis, or non-invasive methods such as a detailed ultrasound scan or a blood test. If a single-gene test is done on an amniotic fluid or CVS sample, you will usually be offered a QF-PCR test as well.
Results of tests for single-gene disorders take different lengths of time. The genetics team will discuss with you how you will get the results of single-gene tests.