Carrier Screening in Pregnancy for Common Genetic Diseases

Although most people have healthy babies, with every pregnancy there is a 3-4% chance to have a baby born with problems. The following are a few common,
serious disorders that can occur even without a family history. You can have carrier screening (a simple blood test) before the baby is born to determine if you carry
the genes that cause the disorders shown below

What is a carrier?

A carrier is a person who has a gene that increases the risk to have children with a specific genetic disease. People do not know if they are carriers until they have a
blood test or an affected child. Some disorders occur only if both parents are carriers and other disorders occur only when the mother is a carrier

What is carrier screening?

Carrier screening involves a blood test from one or both parents to determine if they carry a specific gene that increases the risk for that disorder. If you turn out to
be a carrier, prenatal testing such as amniocentesis or chorionic villus sampling (CVS) is available to determine if your unborn baby is affected. All testing is optional
and you can choose which disorder(s) for which you want to be tested.

Cystic Fibrosis (CF)

Symptoms of Disease

Most common inherited disease in
North America. A chronic disorder
that primarily involves the
respiratory, digestive and
reproductive systems. Symptoms
include pneumonia, diarrhea, poor
growth and infertility.

Inheritance

If both parents are carriers, there is
a 1 in 4 (25%) chance to have a child
with cystic fibrosis.

General Population Carrier Frequency

• 1 in 25 Caucasians
• 1 in 26 Ashkenazi Jewish
• 1 in 46 Hispanics
• 1 in 65 African Americans
• ~ 1 in 90 Asian

Fragile X Syndrome

Symptoms of Disease

The most common inherited cause
of mental retardation. Fragile X
syndrome is a disorder that causes
mental retardation, autism, and
hyperactivity. lt affects both boys
and girls, although boys are usually
more severely affected than girls.
Women who are carriers are at risk
to have a child with mental
retardation.

Inheritance

If a mother is a carrier, there is up
to a 50% chance to have a child with
fragile X syndrome

General Population Carrier Frequency

1 in 260 females in North America
Occurs in all ethnic backgrounds

Spinal Muscular Atrophy (SMA)

Symptoms of Disease

Most common inherited cause of
infant death. SMA destroys nerve
cells that affect voluntary
movement. Infants with SMA have
problems breathing, swallowing,
controlling their head or neck, and
crawling or walking. The most
common form of SMA affects
infants in the first months of life and
can cause death between 2 and 4
years of age. Less commonly the
disease starts later and people can
survive into adulthood. SMA does
not affect intelligence. There is no
cure or treatment.

Inheritance

If both parents are carriers, there is
a 1 in 4 (25%) chance to have a child
with SMA.

General Population Carrier Frequency

• 1 In 35 Caucasians
• 1 in 41 Ashkenazi Jewish
• 1 in 117 Hispanics
• 1 in 66 African Americans
• 1 in 53 Asian