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Downs Syndrome

 

Downs Syndrome Introduction

:downs.jpg Throughout the 20th century, advances in medicine and science enabled researchers to investigate the characteristics of people with Down syndrome (DS). It was in 1959 that Jerome Lejeune, a French physician, identified Downs Syndrome as a chromosomal variance. Prior to this discovery, the characteristics of those with Down syndrome had been observed and not understood. In the late 19th century, John Langdon Down, an English physician, published an accurate description of an individual with Down syndrome. It was his work that earned Down the recognition as the namesake of this condition.

Today, Downs Syndrome is the most well researched genetic disorder. It is characterized by varying degrees of physical and mental retardation, ranging from mild to severe symptoms.

Downs Syndrome is specifically a chromosomal disorder. Chromosomes are the cellular material obtained from our parents, containing the DNA or ‘blueprint’ that determines our genetic makeup. We normally have 23 pairs of chromosomes. However, in persons with Downs Syndrome there is extra genetic material resulting in three copies of chromosome 21. For this reason, Downs Syndrome is also called Trisomy 21. [1] In a small percentage of people with Downs Syndrome, some have an extra bit of chromosome 21 attached to another chromosome, usually chromosome 14. This is called translocation. Finally, an even smaller percentage have a mixed of “mosaic pattern,” meaning that some cells have a normal amount of genetic material, while others have an extra chromosome 21. [2]

The diagnosis of Downs Syndrome is usually suspected after the baby is born and is determined by the infants uncommon physical characteristics. There are blood screening and diagnostic tests that can be performed prior to birth, which can provide more information about the unborn child. Blood screening tests are only about 60% accurate, and can sometimes lead to either a false positive (meaning the test incorrectly indicates that a fetus has Downs Syndrome) or false negative (meaning the test failed to diagnose a fetus with Downs Syndrome). However, blood screening that is done by taking the mother’s blood is less invasive than diagnostic tests and can also be done between 15 and 20 weeks of gestation. While diagnostic tests have a high accuracy rate, they are more invasive and have a risk of causing a miscarriage. This test typically involves sampling the amniotic fluid surrounding the fetus inside the womb.

The risk of having a Downs Syndrome baby increases in women over the age of 35, but because of the higher fertility rates in younger women, most Downs Syndrome babies are born to those younger than 35. There is speculation that in older expecting women, the aging immune system’s ability to police the fetus for chromosomal abnormalities decreases. This would, theoretically, lead to older women carrying Downs Syndrome babies to term, as compared to younger woman who would spontaneously abort a fetus with extra genetic material.

Downs Syndrome Symptoms


Children with Downs Syndrome have varied sign and symptoms in fact there are over 50 clinical signs, but it is rare to find all of them in one person.  Although there is some fluctuation in manifestation, all people with Downs Syndrome have a distinct facial appearance.  Some of the more common features are [3, 4]: 
  • Small nose
  • Flattened face
  • Upward slanting eyes
  • Unusually shaped ears
  • Short neck
  • Small head
  • Small oral cavity

Other common characteristics:

  • Broad feet with short toes
  • Hyperflexibility
  • Poor muscle tone
  • A single crease in the palm
  • Short, broad hands with short fingers

It is common for those with Down syndrome to suffer from other health related problems:

  • Tendency towards obesity
  • Propensity towards respiratory infections
  • Visual problems such as crossed eyes, near or far sightedness
  • Gastrointestinal problems
  • Heart defects
  • Atlantoaxial instability (misalignment of the top two vertebrae of the neck)
  • Visual problems such as crossed eyes
  • Low thyroid function (hypothyroidism)

The physical characteristics of people with Downs Syndrome are not necessarily treated with specific intention; physical problems are treated more often with physical therapy so that the person can better function. The medical conditions that accompany a person with Downs Syndrome are treated much the same way as in people without Downs Syndrome. However, given the combinations that occur together in Downs Syndrome, specific treatments may be needed.

Downs Syndrome Statistics

  • One of every 800 to 1000 live births is a Downs Syndrome baby, which represents about 5,000 births per year in the United States alone.
  • In the United States today, Downs Syndrome affects more than 350,000 people. [5]
  • Hearing loss of more than 15 to 20 decibels in at least one ear occurs is 66- 89% of Downs Syndrome children. [6]
  • There is about a 3% occurrence rate of cataracts in those with Downs Syndrome. [7]
  • As a woman ages, the chances of her giving birth to a baby with Down’s tends to increase.

Mother’s age and Incidence of Down’s Syndrome:

Mothers Age Incidence of Down’s Syndrome
Under 30 Less than 1 in 1000
30 1 in 900
35 1 in 400
36 1 in 300
37 1 in 230
38 1 in 180
39 1 in 135
40 1 in 105
42 1 in 60
44 1 in 35
46 1 in 20
48 1 in 16
49 1 in 12

Source: Hook, E.G., Lindsjo, A. Down Syndrome in Live Births by Single Year Maternal Age.

Downs Syndrome Treatment

There is no medical cure for Downs syndrome, and because of this, the focus of initial treatment is on an early detection of the condition and correction of associated complications of the heart and/or gastrointestinal defects. Since individuals with Down syndrome often have associated health conditions, there is emphasis on management of these problems that often lead to further complications. Many with Downs Syndrome are able to read, write, attend school, and engage in jobs at various skill levels. Intervention at a young age with appropriate sensory, motor and cognitive stimulation may increase the likelihood of that person living an autonomous, functional life.

Supplements helpful for Downs Syndrome

Zinc

Zinc a powerful antioxidant and supporter of immune function has been shown to have a positive effect in those with Downs Syndrome. One study followed 22 children; 16 males and 6 females, who received zinc sulphate over a period of 6 to 9 months. At the conclusion of the study, 15 of the 22 children had reached a higher level on their growth chart. [8]

As discussed, those with Down syndrome can have a host of other health related conditions, one being low thyroid function. Downs Syndrome Adults who supplemented with zinc sulphate that had a low thyroid function showed an improvement in both hypothyroidism and subclinical hypothyroidism. [9] In addition, frequent respiratory infections are better managed and may be resolved more quickly by using zinc. Known to inhibit the replication of certain common viruses, zinc is useful adjunctive treatment in people with recurrent viral infections.

Essential Fatty Acids Docosahexaenoic acid (DHA) and EPA

DHA and EPA are long chain polyunsaturated fatty acids derived from fish, other marine animals, and microalgae. DHA plays a critical role in brain function and is thought to contribute to proper structural, neurologic, and synaptic membrane development. [10] DHA and EPA are incorporated into the brain in large amounts throughout the last part of pregnancy and also in the first months of life. [11] In those with Downs Syndrome, research shows an altered composition of essential fatty acids in the brain. [12] Because of these effects, supplementation with essential fatty acids may help with cognitive function.

Glutathione peroxidase is an enzyme in the body involved with decreasing the activity of free radicals. In those with Downs Syndrome, there is an increase in free radical activity. EPA has been shown to increase levels of Glutathione peroxidase, therefore decreasing free radical damage, and alleviating cellular stress. [13]

Antioxidants

In those with Downs Syndrome, the increased level of oxidative stress warrants therapy that prevents free radical damage. It has been shown that in those with Downs Syndrome, there is a higher activity of superoxide dismutase, an enzyme that could lead to increased oxidative damage. [14] Therefore, it would follow that supplementation with antioxidants would have a positive effect, decreasing the overall oxidative stress on the system.

Researchers at Harvard Medical School examined fetuses with Downs Syndrome in comparison to those with normal brain tissues. When grown in cultures, the Downs Syndrome brain cells had a 3 to 4 fold increase in free radicals and died much more quickly then the normal brain cells. They repeated the culture, but this time the Downs Syndrome cells were pretreated with different antioxidants. Some of the treatments were able to greatly increase the number of sustainable cells compared to those given no antioxidant support. Among the most effective antioxidants were vitamin E and N-acetyl-cysteine. [15]

Vitamins A, C, E, selenium, and zinc all have powerful antioxidant effects that have been shown, in many research studies, to have a positive effect on decreasing oxidative stress. Many reports also show that Downs Syndrome individuals have low serum antioxidant levels, and that antioxidant supplementation would be beneficial. [16, 17]

B12 and Folate/folic acid

B12 is a water-soluble vitamin needed for proper cell division and cell maturity, nerve cell conduction, and DNA replication. Studies suggest that those with Downs Syndrome have abnormal blood cells. This suggests that there may be a deficiency in both B12 and folic acid in these individuals. Furthermore, it is common for children to have diminished gastrointestinal function, which leads to decreased absorption of nutrients and vitamins.

More specifically, research suggests that some with Downs Syndrome can have a B12 deficiency. [18] Deficiency of folic acid and B12 in pregnant women is a well-established cause of neural tube defects in their children. [19] There seems to be a relationship with those at risk for neural tube defects and Downs Syndrome. Mothers of babies with neural tube defects (NTDs) have been found to have problems metabolizing folic acid, which may also be a risk factor for Downs Syndrome as well. In one study involving 493 families who had had a previous pregnancy affected by NTD and 516 families who had had a pregnancy affected by Down’s syndrome, there were five times the number of children born with Down syndrome among the neural tube defect group as expected from women of the same age. [20]

5-Hydroxytryptophan (5-HTP)

5-HTP is similar to the amino acid L-tryptophan and the neurotransmitter serotonin. In the body, L-tryptophan converts to 5-HTP that is then transformed to serotonin. The main role of 5-HTP is to increase circulating levels of serotonin in the central nervous system. Serotonin plays many roles in the body; some of which are appetite modulation, mood and behavior regulation, and sleep pattern development. Some studies show that in Downs Syndrome children, there are low levels of serotonin and that the administration of 5-HTP improves muscle tone and reduces tongue protrusion (a common physical characteristic in Downs Syndrome). [21, 22]

References

[1] Online source: http://www.pdrhealth.com/drug_info/nmdrugprofiles/herbaldrugs/101840.shtml

[2] Online source: http://www.pdrhealth.com/drug_info/nmdrugprofiles/herbaldrugs/101840.shtml

[3] Online source: http://www.pdrhealth.com/drug_info/nmdrugprofiles/herbaldrugs/101840.shtml

[4] Online source: http://www.pdrhealth.com/drug_info/nmdrugprofiles/herbaldrugs/101840.shtml

[5] Online source: National Down Syndrome Society: http://www.pdrhealth.com/drug_info/nmdrugprofiles/herbaldrugs/101840.shtml

[6] http://www.nichd.nih.gov/publications/pubs/downsyndrome/down.htm#TheOccurrence

[7] ibid

[8] Napolitano G, Palka G, Grimaldi S, Giuliani C, Laglia G, Calabrese G, Satta MA, Neri G, Monaco F. Growth delay in Down syndrome and zinc sulphate supplementation. Am J Med Genet Suppl. 1990;7:63-5.

[9] Napolitano G, Palka G, Lio S, Bucci I, De Remigis P, Stuppia L, Monaco F, Is zinc deficiency a cause of subclinical hypothyroidism in Down syndrome?, Ann Genet. 1990;33(1):9-15

[10] Moriguchi T, Greiner RS, Salem N Jr. Behavioral deficits associated with dietary induction of decreased brain docosahexaenoic acid concentration. J of Neurochem 2000;75:2563-73.

[11] Wainwright P. Nutrition and behaviour: the role of n-3 fatty acids in cognitive function. Br J Nutr 2000;83:337-9.

[12] Brooksbank BW, Martinez M, Balazs R, Altered composition of polyunsaturated fatty acyl groups in phosphoglycerides of Down’s syndrome fetal brain. J Neurochem. 1985 Mar;44(3):869-74.

[13] Joulain, C., et al. (1994) Increased glutathione peroxidase activity in human blood mononuclear cells upon in vitro incubation with n-3 fatty acid. Biochem-Pharmrol. 47(8), 1315-1323.

[14] Gulesserian T, Seidl R, Hardmeier R, Cairns N, Lubec G. Superoxide dismutase SOD1, encoded on chromosome 21, but not SOD2 is overexpressed in brains of patients with Down syndrome. J Investig Med. 2001 Jan;49(1):41-6.

[15] Busciglio, J. & Yanker, B. (1995) Apoptosis and increased reactive oxygen in Down’s syndrome neurons in vitro. Nature. 378, 776-778.

[16] Colombo MI, Girdardo E, Incarbone E, Conti R, Ricci BM, Maina D. Vitamin C in children with trisomy 21. Minerva Pediatr,1989;41(4):189-192

[17] Cengiz M, Seven M. Vitamin and mineral status in Down syndrome. Trace Elem Elec 2000;17(3):156-160

[18] PH Cartlidge and DA Curnock, Specific malabsorption of vitamin B12 in Down’s syndrome, Archives of Disease in Childhood, Vol 61, 514-515

[19] Steen MT, Boddie AM, Fisher AJ, Macmahon W, Saxe D, Sullivan KM, Dembure PP, Elsas LJ. ,Neural-tube defects are associated with low concentrations of cobalamin (vitamin B12) in amniotic fluid., Prenat Diagn. 1998 Jun;18(6):545-55.

[20] Barkai G, Arbuzova S, Berkenstadt M, Heifetz S, Cuckle H, Frequency of Down’s syndrome and neural-tube defects in the same family., Lancet April 19, 2003;361:1331-35

[21] Bazelon M, Paine RS, Coeiw VA, et al. Reversal of hypotonia in infants with Down’s syndrome by administration of 5-hydroxytryptophan. Lancet 1967;1:1130–3.

[22] Coleman M. Infantile spasms associated with 5-hydroxytryptophan administration in patients with Down’s syndrome. Neurology 1971;21:911–9.