Down Syndrome

Down Syndrome refers to a common genetic disorder that results in birth defects, medical problems and some degree of mental retardation.

Causes

Down Syndrome results from a genetic error. Cells carry genetic information on chromosomes. Each normal egg and sperm has 23 chromosomes, numbered 1 through 23. A normal fertilized egg has 23 pairs of chromosomes, one set from each parent. Down yndrome results from a third copy of chromosome 21. In most cases, the extra chromosome is passed on to all cells as the fetus develops. A small percent of those with Down syndrome only have the extra chromosome in some cells. Another small group of patients have extra material from chromosome 21 attached to a different chromosome.

Risk Factors

A risk factor is something that increases your chance of getting a disease or condition.
  • Age: The chance of having a child with Down syndrome increases after a woman reaches age 35.
  • Genetics: If either parent is a carrier of a specific type of Down syndrome (Translocation Down Syndrome), there is an increased risk of giving birth to a child with this type of Down syndrome.
  • Sex: More boys are born with Down syndrome.

Symptoms

Infants born with Down Syndrome may have some or all of the following physical characteristics:
  • Flat facial features
  • Slanted eyes
  • Short neck
  • Misshaped ears
  • White spots on the colored part of the eye
  • Skin crease in the palm of the hand
  • Poor muscle tone
  • Excess flexibility in joints
  • Heart defects
  • Sight and hearing problems
  • Large and protruding tongue
  • Finger and toe malformations
The degree of medical problems and mental retardation varies. Talents, abilities and pace of development differ. People with Down Syndrome may be born with or develop:
  • An under-active thyroid (hypothyroidism)
  • Hearing loss
  • Heart defects
  • Urinary system defects
  • High blood pressure in the lungs
  • Seizures
  • Poor muscle tone
  • Constipation or bowel obstruction
  • Improperly formed spine
  • Problems with spinal cord development
  • Leukemia
  • Infections
  • Slow growth
  • Late to sit, walk, toilet train
  • Speech problems
  • Obesity
  • Emotional problems
  • Premature aging
  • Dementia at an early age

Diagnosis

Doctors can usually identify a child born with Down Syndrome at delivery.
Tests include:
Blood Test – to check for the extra chromosome
Tests before delivery include:
Triple Screen – measures quantities of certain substances in the blood
Alpha-fetoprotein Screening – also measures quantities of certain substances in the blood
Amniocentesis – tests cells from the developing fetus to examine the fetus's chromosomes
Chorionic Villus Sampling – tests cells from the developing fetus to examine the fetus's chromosomes
Percutaneous Umbilical BloodSampling – tests cells from the developing fetus to examine the fetus's chromosomes

Treatment

There are no medical treatments available to reverse Down Syndrome. Some newborns with Down Syndrome may need surgery to repair serious defects. Living at home and receiving special therapy helps children with Down Syndrome achieve their full potential. Most people with the condition can actively participate in the community.
Baby Care
Infants with Down Syndrome may take longer to feed. A child with the condition will start talking, playing and performing other activities later than normal.
Education
School programs designed to meet the child's special needs may help to increase learning opportunities. Children who have accomplished academic milestones may be mainstreamed into regular public school classes, with additional support as required.
Rehabilitation Services
Speech, physical and occupational therapy may improve the ability to speak, walk and perform activiies of daily living.
Social Services
Professional support helps a family cope with caring for a child with birth defects and mental retardation. Mental health professionals offer help with managing emotional problems.

Prevention

There are no guidelines for preventing Down Syndrome. If you have concerns about having a child with Down Syndrome consider getting genetic counseling prior to becoming pregnant.