Facts and FAQ About Down Syndrome
Is babies with Down syndrome only born to older women?
Women over the age of 35 haver a higher chance of having a child with Down syndrome. Nevertheless, more than 80% of children with Down syndrome are currently being born to mothers under the age of 35, due to higher fertility and birth rate in younger mothers.
What is the cause of Down syndrome?
The cause of the extra full or partial chromosome is still unknown. Age is the only factor that has been linked to an increased chance of having a baby with Down syndrome. However due to higher birth rates amongst women, 51% of children with Down syndrome are born to younger women under the age of 35 years of age.
What is the incidence of Down syndrome?
Down syndrome occurs equally across all races, religions, and socio-economic backgrounds. The incidence is approximately 1-500 live births in developing countries.
Are there different types of Down syndrome?
There are three types of Down syndrome:
- Trisomy 21 – about 95% of people born with Down syndrome have Trisomy 21, with this type of Down syndrome, each cell has three separate copies of chromosome 21 instead of two copies.
- Translocation Down syndrome – This accounts for about 3% of cases of Down syndrome. This occurs when a full or partial extra copy of chromosome 21 is present, but it is attached or “trans-located” to a different chromosomal pair, usually chromosome 14.
- Mosaicism – Mosaicism or Mosaic Down syndrome accounts for about 2% of cases and occurs when there is a mixture of two types of cells, some containing the usual 46 chromosomes and some containing 47 chromosomes.
Important: Regardless of the type of Down syndrome, all people born with Down syndrome have an extra, critical portion of chromosome 21 present in all or some of their cells.
There are two types of screening tests:
Prenatal Screening Test: A screening test can tell a woman whether her pregnancy has a lower or higher chance of a baby with Down syndrome. Screening tests do not provide a definitive diagnosis.
Diagnostic Test: Diagnostic tests can provide a definitive diagnosis, with almost 100% accuracy.
Screening tests often include a combination of a blood test, which measures the amount of various substances in the mother’s blood. An ultrasound, which creates a picture of the baby. During an ultrasound, one of the things the technician looks at is the fluid behind the baby’s neck. Extra fluid in this region could indicate a genetic problem.
Diagnostic tests are usually performed after a positive screening test to confirm a Down syndrome diagnosis. Types of diagnostic tests include:
- Chorionic villus sampling (CVS)—examines material from the placenta. Performed in the first trimester between 11-14 weeks of gestation.
- Amniocentesis—examines the amniotic fluid (the fluid from the sac surrounding the baby). Performed in the second trimester 15-20 weeks of gestation.
Both these tests carry 1% risk of miscarriage
Are there any additional health concerns?
- Hearing loss
- Obstructive sleep apnea, which is a condition where the person’s breathing temporarily stops while asleep
- Ear infections
- Eye diseases
- Heart defects present at birth
With advancement in medical treatment, health care providers routinely monitor children with Down syndrome for these conditions. Early diagnosis and services such as early intervention therapies can help babies and children improve their physical and intellectual abilities.
How will a baby with Down syndrome affect my family?
Like all babies, babies born with Down syndrome require the same love and care as any typical baby, so celebrate the birth of your baby. Quality education, a loving and stimulating home environment, good healthcare and positive support from family, friends, and community can enable persons with Down syndrome to lead fulfilling and productive lives.