The risk of chromosome disorders like DS, trisomy 13 and trisomy 18 increases with maternal age. If a couple has a child with DS, there is usually an increased risk for a second affected child.
What is Down Syndrome? People with Down syndrome are first and foremost human beings who have recognizable physical characteristics and limited intellectual endowments which are due to the presence of an extra chromosome The estimated incidence of Down syndrome is between 1 in 1, to 1 in 1, live births.
Each year approximately 3, to 5, children are born with this chromosome disorder.
It is believed there are aboutfamilies in the United States who are affected by Down syndrome. How do children with Down syndrome develop?
Children with Down syndrome are usually smaller, and their physical and mental developments are slower, than youngsters who do not have Down syndrome. The majority of children with Down syndrome function in the mild to moderate range of mental retardation.
However, some children are not mentally retarded at all; they may function in the borderline to low average range; others may be severely mentally retarded. There is a wide variation in mental abilities and developmental progress in children with Down syndrome. Also, their motor development is slow; and instead of walking by 12 to 14 months as other children do, children with Down syndrome usually learn to walk between 15 to 36 months.
Language development is also markedly delayed. It is important to note that a caring and enriching home environment, early intervention, and integrated education efforts will have a positive influence on the child's development.
What are the physical features of a child with Down syndrome? Although individuals with Down syndrome have distinct physical characteristics, generally they are more similar to the average person in the community than they are different. The physical features are important to the physician in making the clinical diagnosis, but no emphasis should be put on those characteristics otherwise.
Not every child with Down syndrome has all the characteristics; some may only have a few, and others may show most of the signs of Down syndrome.
Some of the physical features in children with Down syndrome include flattening of the back of the head, slanting of the eyelids, small skin folds at the inner corner of the eyes, depressed nasal bridge, slightly smaller ears, small mouth, decreased muscle tone, loose ligaments, and small hands and feet.
About fifty percent of all children have one line across the palm, and there is often a gap between the first and second toes. The physical features observed in children with Down syndrome and there are many more than described above usually do not cause any disability in the child.
How may chromosome subtypes are observed in Down syndrome?
There are three main types of chromosome abnormalities in Down syndrome: The vast majority of children with Down syndrome approximately 95 percent have an extra 21 chromosome. Instead of the normal number of 46 chromosomes in each cell, the individual with Down syndrome has 47 chromosomes.
This condition is called trisomy The second type is called translocation since the extra 21 chromosome is attached or translocated on to another chromosome, usually on chromosome 14, 21 or If translocation is found in a child with Down syndrome, it is important to examine the parents' chromosomes, since in at least one-third of the cases, a parent may be a carrier of the translocation.Down Syndrome: free Medicine sample to help you write excellent academic papers for high school, college, and university.
Check Out Our Down Syndrome Essay. The long arms of these two acrocentric chromosomes are translocated to generate a sole long chromosome, leaving out the short arm which fails to separate out, therefore lessening. PHYSIOLOGY OF FLOWERING. Plants, to begin with go through a period of vegetative growth.
The extent of vegetative growth is endowed with its genetic potentiality. Translocation Writing Service. In Down syndrome, most translocations are Robertsonian translocations including chromosome Translocation Writing Service.
In genetics, the motion of a part of one chromosome to another; in protein synthesis, the transfer of the newly elongated peptidyl-tRNA from the amino acyl to the peptide . For centuries, people with Down syndrome have been alluded to in art, literature and science.
It wasn’t until the late nineteenth century, however, that John Langdon Down, an English physician, published an accurate description of a person with Down syndrome.
Down syndrome is a condition caused by chromosome replication errors.
A baby born with Down syndrome may have symptoms such as unusual facial features, low IQ, and difficulty learning to walk and crawl.
Someone with Down syndrome may have a shorter life expectancy. Learn more facts about Down syndrome in this article. A baby born with Down syndrome has various elements associated with the fertilized egg, characteristics of a newborn with Down syndrome and the chromosome aspect.
A child is still a child whether they have a high risk disorder or the child has been born without.