January 20, 2024

Carrier Screening

Understanding Carrier Screening

Carrier screening is a genetic test that reveals whether you carry a DNA change that could lead to a genetic disorder in your child. Because carriers often do not display any symptoms associated with the genetic disorder they carry, screening is a valuable tool that helps individuals and couples gain insights into potential genetic risks for their children. 

Why is Carrier Screening Important?

If you carry a DNA change, your children may be at risk of developing a genetic disorder. Most disorders targeted by carrier screening are known as recessive genetic disorders, though some are X-linked. Recessive genetic disorders typically require the presence of two abnormal copies of a gene. For a child to be at risk of inheriting a recessive genetic disorder, both parents must be carriers of the same condition.

X-linked disorders are associated with genes located on the X chromosome. In the context of carrier screening, this means that women may carry a genetic change on one of their X chromosomes without showing symptoms, but they can potentially pass it on to their children. In the case of X-linked disorders in women, each pregnancy carries a 50% chance of being affected by the disorder.

Chances if Both Parents are Carriers?

If both parents are carriers of the same autosomal recessive condition, there’s a 25% chance of having an affected child in each pregnancy. Being aware of your carrier status assists you and your physician in making informed decisions regarding pregnancy planning.

Who Should Have Carrier Screening?

If you have a family history of genetic disorders, discussing it with your doctor is essential. They may refer you to a genetic counselor to assess your family history and determine if additional genetic testing is necessary. However, anyone can be a carrier of a genetic condition, including healthy individuals with no family history of a genetic disorder. Carrier screening is not just for those with known family histories; it’s for everyone planning to have children.

Positive Results and Partner Screening

If your carrier screening results are positive, it’s crucial to screen your partner to assess the risk of recessive genetic disorders in your children. HNL Lab Medicine conducts partner screening for the same genetic disorder at no additional charges for eligible individuals.

When to Undergo Carrier Screening?

While carrier screening is best done before getting pregnant, it can also be done during pregnancy. Knowing your carrier status before pregnancy helps you make informed decisions about the best reproductive options for you, including considering advanced reproductive technologies.

Testing Process and Results

Once you and your doctor decide on carrier screening tests, your doctor will place an order for the tests. You can then visit any HNL Lab Medicine Patient Service Center to have your blood drawn. Results are typically available within 7-14 days and can be accessed on MyHNLAccess.com, the HNL Lab Medicine patient portal.

Conditions Screened and HNL Lab Medicine’s Offerings

HNL Lab Medicine offers carrier screening for 46 recessive and X-linked genetic disorders, including cystic fibrosis, spinal muscular atrophy, Fragile X, and sickle cell disease.

  • Cystic Fibrosis is characterized by thick, sticky mucus affecting organs. Modern treatments allow many to live well into adulthood.
  • Spinal Muscular Atrophy (SMA) causes muscle weakness, with severity differing in types. The most severe form, type I, manifests within the first few months of life.
  • Fragile X causes developmental problems, learning disabilities, and cognitive impairment. This condition is more severe in males; female carriers may experience premature ovarian failure.
  • Sickle Cell Disease affects hemoglobin, causing anemia, infections, and pain episodes. Severity varies among individuals.

Understanding and considering carrier screening is a proactive step towards ensuring the health and well-being of your future family. If you have any concerns or questions, consult with your healthcare provider for personalized guidance.