Down syndrome is a genetic condition that leads to mental retardation for life, delays in development and other disabilities. The severity of Down syndrome tends to vary and hence the developmental difficulties can range from moderate to profound.
Down syndrome is the most frequent genetic form of learning deficits in children. Early interventions as well as better understand of the condition have resulted in bettering the quality of life led by both the children and adults affected by Down syndrome.
Down syndrome statistics
- During the period between 1979 to 2003, the incidence of Down syndrome from birth increased by nearly 31 %, from 9 to about 12 in every 10,000 live births in ten regions of the United States. During 1997 to 2003, from among these ten US regions, the birth incidence of Down syndrome was at a low of 9.7 in Arkansas and at a high of about 13.7 in Utah.
- The birth of babies with Down syndrome in older mothers was at nearly 38.6 every 10,000 births, which is estimated to be nearly 5 times more than those born to younger mothers, which was estimated to be about 7.8 every 10,000 births
- In the year 2002, it was found that 1 in every 1000 children and teens aged between 0 to 19 years and living in the ten US regions were afflicted with Down syndrome. This indicated that an estimated 83,000 children and teens with Down syndrome were living in the United States that particular year.
- The incidence of Down syndrome was the highest in the age group 0 to 3 years old at 11.1, which depreciated to 10.3 in 4 to 7 year olds, 9.8 in 8 to 11 year olds, 8.3 in 12 to 15 year olds, and 6.0 in 16 to 19 year olds
- In the same year the incidence of Down syndrome in 0 to 19 year olds was the lowest among Non-Hispanic black people at 7.3. The incidence of the disorder in Non-Hispanic white people was at 10.2, at 12.3 in Hispanics and at 8.9 in people belonging to other ethnicities or races. Also, the incidence of Down syndrome in 0 to 19 year old males was higher at 10.8 as compared to females with an incidence of 9.7.
Symptoms of Down syndrome
Individuals affected by Down have unique facial features which may differ from one affected child to another. Some common signs and symptoms of Down syndrome are as follows:
- A small head
- Facial characteristics may have a flattened appearance
- The neck may be short
- The child may have eyes with an upward slant that may be unusual for his/her ethnicity
- The tongue may bulge out
- The ears are abnormally shaped
Affected individuals may also display the below listed signs:
- Impaired muscle tone
- The fingers may be comparatively short
- The hands may be short and broad with only a single crease in the palm
- Increased flexibility
Children with Down syndrome tend to grow to an average height, but generally tend to grow slowly and therefore remain shorter as compared to children of the same age.
Additionally, the achievement of various developmental milestones such as sitting, crawling and walking is severely delayed in children with Down syndrome. They may also develop some form of mental retardation that may range from mild to moderate.
What causes Down Syndrome ?
The human cells generally have 23 pairs of chromosomes. One chromosome present in each pair is inherited from the mother, and the other from the father
Down syndrome is caused when there is abnormal cell division in chromosome 21. This abnormal cell division may occur in three forms, and all three types lead to additional genetic material in chromosome 21. Such changes lead to the characteristic developmental delays and distinct facial features associated with Down syndrome.
The three types of genetic abnormalities are discussed below:
- A child with three copies of chromosome 21 instead to two copies in all the cells of the body, is said to have trisomy 21 type of Down syndrome. More than ninety percent of the children with Down syndrome have the trisomy 21 type. This type is generally caused due to abnormal cell division that occurs during the making of the maternal egg or the paternal sperm.
- The translocated form of Down syndrome is uncommon and develops when a part of chromosome 21 attaches or translocates onto some other chromosome. This may happen pre or post conception. Children with this form of Down syndrome have 2 copies of the chromosome 21, but have other chromosomes that may have parts of chromosome 21 attached to them.
- The mosaic form of Down syndrome is caused due to abnormal cell division post fertilization and results in the presence of three copies of chromosome 21 in only some cells of the body.
Down syndrome Treatment
There is no cure for Down syndrome.
Screening for the presence of Down syndrome in the child during pregnancy as well as early intervention programs are some of the ways of alleviating the signs and symptoms of the disorder.
- Blood tests and ultrasound may be done during week 11 to 13 of pregnancy
- Full integrated testing during pregnancy is another way to screen the baby for Down syndrome
- Pregnant women can opt for diagnostic tests like amniocentesis, percutaneous umbilical blood sampling and chorionic villus sampling if they feel that the baby has a high risk to developing Down syndrome
- Early intervention programs can assist the child with Down syndrome to inculcate language, motor, social and self-help skills to overcome the effects of delayed development and other symptoms of Down syndrome.
Down Syndrome life expectancy
Down Syndrome patients pose higher risk for many conditions, mainly chronic neurodegenerative diseases like Parkinson’s Disease, Huntington’s, Alzheimer’s Disease etc. The presence of extra genetic matter can impact organs as well as life processes, leading to shorter life expectancy. However, progress in the field of medical technology and better healthcare has led to increase in the life expectancy of Down syndrome patients. In fact, in March 2012, the Guinness Book of World Records stated that London resident, Joyce Greenman, who was born on March 14, 1925, at the age of 87, is the oldest living person with Down Syndrome.
Down Syndrome pictures