Down syndrome was named after John Langdon Down, the first physician to identify the syndrome.  Down syndrome is the
most frequent genetic cause of mild to moderate mental retardation with associated medical problems. Down syndrome
occurs in one out of 800 live births, in all races and economic groups. Down syndrome is a chromosomal disorder caused by
an error in cell division that results in the presence of an additional third chromosome 21 or "trisomy 21." When the fertilized
egg contains extra material from chromosome number 21, the result is a child with Down syndrome. This disorder includes a
combination of birth defects; among them are some degree of mental retardation, characteristic facial features and, often,
heart defects, increased infections, problems with vision and hearing, and other health problems.

Genetics of Down Syndrome

Comprehending why Down syndrome occurs, the structure and function of the human chromosome must be understood.
The human body is made of cells; all cells contain chromosomes, structures that transmit genetic information. Most cells of
the human body contain 23 pairs of chromosomes, half of which are inherited from each parent. When the reproductive cells,
the sperm and ovum, combine at fertilization, the fertilized egg that results contains 23 chromosome pairs. Three genetic
variations can cause Down syndrome. In most cases, approximately 92% of the time, Down syndrome is caused by the
presence of an extra chromosome 21 in cells of the individual. When the egg and sperm unite to form the fertilized egg, three
rather than two chromosomes 21 are present resulting in Down syndrome.

Down syndrome is not attributable to any behavioral activity of the parents or environmental factors. Researchers have
extensively studied the defects in chromosome 21 that cause Down syndrome. In 88% of cases, the extra copy of
chromosome 21 is derived from the mother. In 8% of the cases, the father provided the extra copy of chromosome 21. In the
remaining 2% of the cases, Down syndrome is due to the forming of 2 cells from one; an error in cell division occurs after
fertilization when the sperm and ovum are joined.

Maternal Age

The incidence of Down syndrome rises with increasing maternal age. Researchers have established that the likelihood that a
reproductive cell will contain an extra copy of chromosome 21 increases dramatically as a woman ages. However, of the total
population, older mothers have fewer babies; about 75% of babies with Down syndrome are born to younger women because
younger women are more likely to become pregnant. Many specialists recommend that women who become pregnant at age
35 or older undergo prenatal testing for Down syndrome. The likelihood that a woman under 30 who becomes pregnant will
have a baby with Down syndrome is less than 1 in 1,000, but the chance of having a baby with Down syndrome increases to
1 in 400 for women who become pregnant at age 35 or older, about 25% of babies with Down syndrome are born to women
in this age group. The probability that another child with Down syndrome will be born in a subsequent pregnancy is about 1
percent, regardless of maternal age.

Diagnosis of Down Syndrome

A newborn baby with Down syndrome often has physical features the attending physician will most likely recognize in the
delivery room. These may include a flat facial profile, an upward slant to the eye, a short neck, abnormally shaped ears, white
spots on the iris of the eye (called Brushfield spots), and a single, deep transverse crease on the palm of the hand. However, a
child with Down syndrome may not possess all of these features; some of these features can even be found in the general
population.

To confirm the diagnosis, the doctor will request a blood test called a chromosomal karyotype. This involves "growing" the
cells from the baby's blood for about two weeks, followed by a microscopic visualization of the chromosomes to determine if
extra material from chromosome 21 is present.

Caring for Children with Down Syndrome

When parents are told that their newborn baby has Down syndrome, it is not unusual for them to have feelings of sadness,
disappointment and anxiety. Medical care for infants with Down syndrome should include the same well-baby care that other
babies receive. With the diagnosis of Down syndrome it’s unknown the intellectual or physical capabilities this child, or any
other child, you may have. Children and adults with Down syndrome have a wide range of abilities. A person with Down
syndrome may be very healthy or they may present unusual and demanding medical and social problems. Every person with
Down syndrome is a unique individual, and not all children with Down syndrome will develop medical disorders.

Early Childhood Development

Children with Down syndrome may be developmentally delayed. A child with Down syndrome is often slow to turn over, sit,
stand, and respond. This may be related to the child's poor muscle tone. Development of speech and language abilities may
take longer than expected and may not occur as fully as parents would like. However, children with Down syndrome do
develop the communication skills they need. Parents should keep in mind that children with Down syndrome have a wide
range of abilities and talents, and each child develops at his or her own particular pace. It may take children with Down
syndrome longer than other children to reach develop- mental milestones, but many of these milestones will eventually be met.
Down Syndrome
Down Syndrome, What is Down Syndrome Bright Tots - Information on child development - Autism information.  www.brighttots.com
Down Syndrome
Printer Friendly Copy
Resources

Resource Home

Asthma

Baby Tooth Decay

Behavioral Disorders

Child Safety Tips

Disorders Home

Early Intervention

FMLA for Parents

Learning Disability

Parenting Issue

Preschool Special Ed.

Parenting Help

Speech Disorders

Weight Concern

Autism

Asperger's Syndrome

Childhood Disintegrative
Disorder

Early Signs of Autism

Echolalia
(Repetitive Speech)

Fragile X

Hyperlexia

Low Functioning Autism
(Classic Autism)

PDD-NOS
Pervasive Developmental
Disorder

Rett Syndrome

Savant Syndrome

Semantic Pragmatic Disorder
For more information and articles on autism visit:
www.worldofautism.com
Choosing the Right Toy for :
Babies      Toddlers      Preschool
World of Autism

What is Autism?  Frequently asked questions on autism - What causes autism?  What is Applied Behavior Analysis (ABA
Therapy)?  Autism Diagnosis - What are the Types of Autism, What are the signs of Autism?  Medications used in
treatment of Autism - A Genetic Clue to Why Autism Affects Boys More - Autism and Vaccines - 1 in 68 Children
affected with Autism - Autism: To Cure or Not to Cure - Speech and Language Problems in Autism Spectrum Disorders -
Research Points to Genetic Link in Autism - Challenges Siblings of Children with Autism Face.

Autism Articles

Inspirational uplifting news articles on Autism / The Downside of Autism in the News
Mom Wins Fight for Autism Insurance
Bright Tots ~ Information on childhood developmental disorders, including autism, attention deficit disorder (ADHD),
behavior disorders, bipolar disorder, cerebral palsy, childhood disintegrative disorder, depression in children, diabetes in
children, down syndrome, emotional disorders, obsessive compulsive disorder , selective mutism, separation anxiety
disorder, speech and language disorders and spina bifida.

Resources, articles and information on autism including Asperger's syndrome, assessing autism, autism and tantrums,
autism in childhood, autism therapies, characteristics of autism, discipline strategies, early signs of autism, echolalia,
fragile x, hyperlexia / dyslexia, immunization worries, oral care and autism, pervasive developmental disorders (PDD), Rett
syndrome, savant syndrome, and more...

Understanding
developmental disorders - Find Early Intervention in your area.

Information and articles on
autism therapy and autism treatment including: ABA therapy, autism diets, chelation therapy,
cognitive behavior therapy, key to learning, medications for treating autism, play therapy, occupational therapy, physical
therapy, sensory integration, signed speech, speech therapy, TEACCH Method and more...

What is a learning disability? What are developmental domains? Tips on teaching a child with autism, age appropriate
behavior (milestones), parenting rules, oral care and autism, baby tooth decay, is your child over weight? For those hard to
understand terms, visit our
Glossary.

Bright Tots - Helpful information for picking the right toy for Babies, Toddlers and Preschool kids
What to look for in developmental baby, toddler and preschool toys. Read on the importance of choosing the right
educational baby toys, educational toddler toys, educational preschool toys that will

"Make Learning Fun"

Choosing the right Baby Toys | Toddler Toys | Preschool Toys | Special Needs
Autism Resources

Autism Home

ABA Therapy

Assessing Autism

Autism Diets

Autism Treatments

Autistic Behaviors

Characteristics of
Autism

Cognitive Behavior
Therapy

Early Intervention

Early Signs of Autism

Keys to Learning

Learning to Learn

Medication and Autism

Myths of Autism

Occupational Therapy

Parenting Rules

Physical Therapy

Sensory Integration

Teaching Play Skills

TEECCH Method
Shopping Tips:

Shopping Resources

Baby Toy Guide

Toddler Toy Guide

Preschool Toy Guide

Sp. Needs Toy Guide


*the links below will open in
a new browser*

About Us

Contact Us

Glossary

Info Page

Privacy Policy

Link Partners

Link Exchange
Autism Diets     Autism Information     Developmental Disorders     Parenting Issues