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Stem Cell Treatments to Relieve Symptoms in Down Syndrome
#1
Down syndrome is a genetic disorder caused by the abnormal presence of the entire or a part of an extra chromosome 21. The disorder is named after John Langdon Down, a British doctor who described disease in 1866. The disease is sometimes referred to as “mongolism” and “Mongolian idiocy.” The typical patient suffering from Down syndrome has a total of 47 chromosomes in all the somatic cells of the body. Such an abnormality accounts for the impaired growth and development of the child.

Down syndrome is the leading genetic cause of mental retardation. Statistics report the incidence of Down syndrome to be 1 per 800 live birth babies, making it one of the most frequently inherited chromosomal disorders. These statistics are profoundly influenced by the age of the mother at the time of birth.

People with Down syndrome have very distinct common physical features, which include a flat face, a almond-shaped eyes, epicanthic folds of the eyelids, a small broad nose, abnormally shaped ears, a large protruding tongue, and shorter limbs, a larger-than-normal space between the first and second toes, poor muscle tone... They have also increased risk for respiratory infections, congenital heart defects, gastrointestinal obstruction, and obstructive sleep apnea, thyroid dysfunction, hearing loss, leukemia and Alzheimer’s disease.

Diagnose

There are two types of tests check for Down syndrome during a woman's pregnancy.

Screening test indentify a mother who probably carries a baby with Down syndrome. The most commonly used screening tests are the double and triple screen, also known as triple test, multiple marker screening and alpha fetoprotein plus. Screening may be a maternal blood test done in the first trimester with a special ultrasound to measure the thickness at the back of the baby’s neck (called nuchal translucency). And it can be also done a maternal blood test in the second trimester without the ultrasound. However, screening tests cannot diagnose Down syndrome or other genetic disorder. The diagnosis must be confirmed by a chromosome study (karyotype).

Diagnostic test confirm a positive result identified in a screening test. The most common are amniocentesis, chorionic villus sampling (CVS), and percutaneous umbilical blood sampling (PUBS). Each of them takes a sample from the amniotic fluid, placenta, or umbilical cord to examine the baby's chromosomes and determine an extra chromosome 21.

Therapy

Until now there was no cure for Down syndrome. Only physical therapy and speech therapy could be helpful and made life easier for patients. Following the medical problems associated with the disorder could often improve quality of life.

Stem Cells Research

A large number of Down syndrome children had already been treated with Stem Cell therapy. The results concluded that there is a statistically significant improvement in height, concentration, IQ, speech, motor skills and immune system. Stem cell therapy carried out at an early stage the typical features of Down syndrome become less pronounced and the immunological deficiencies are corrected. This syndrome is one of many conditions which have responded dramatically to stem cell therapy.

Scientists used stem cells from the developing human brain, and grow them in spherical aggregates called neurospheres. They used neurospheres from post-mortem fetuses (with and without Down syndrome), and biochemically induced to form nerve cells. The RNA proteins were extracted from the neurospheres and compared with the RNA proteins from normal neurospheres. After all experiments, it was found that one specific protein was absent from te neurospheres of patients with Down syndrome. The SCG10 gene was relatively or absolutely functionally deficient. They also discovered that certain other genes were also underexpressed, such as L1, Synapsin, and ß4- tubulin. The neurons from the defective stem cells were shorter, irregular, had misshapen axons, and fewer dendrites projected from the main body of the neuron when compared with the control.

Stem cell research discovered a substantial disorder in the genetics of the development of neurons that begins in the earliest stages of formation of the embryo with Down syndrome, resulting form a disruption of expression of certain genes of the neurons.

Cord Stem Cells Treatment

Cord blood is collected because it contains stem cells which are genetically unique. Umbilical cord blood contains stem cells of blood, a very limited amount of mesenchymal cells, and immune cells. These stem cells, at modern time, are very used for the research, how to induce regeneration in various neurological disorders, such as also Down's syndrome. Human fetal stem cell transplants are a new area.

New studies have shown that mesenchymal and CD34 stem cells from umbilical cord blood in combination with grow factor, neurotropic and antioxidant supplements, and stem cell nutrition offers the potential to increase brain tissue development and stop the production of the abnormal protein which interferes with such development.

Patients with Down syndrome had already been treated with cord driven stem cell therapy before the age of 15. The results concluded that there is a statistically significant improvement physical and mental characteristics. The typical features of Down syndrome become less pronounced and the immunological deficiencies are corrected, when treatment is applied earlier.

Umbilical cord stem cells hold promise for reducing some of the symptoms of Down syndrome. This is a new, exciting frontier for human umbilical cord stem cells.

Research efforts aspire to examine the role of individual genes developing Down syndrome and to determine why those individuals with this condition are particularly vulnerable to diseases like leukemia and autoimmune disease. Stem cell research in Down syndrome offers hope in detecting individual genes, which are responsible for complex conditions, such as hypertension, diabetes, and to create artificial chromosomes for gene therapy. There is not a specific cure for Down syndrome at present, but researchers believe that gene therapy will enhance therapeutic options for such people, in the future. A patient with Down could benefit from drugs that could help regulate proper gene expression. At the pace of present research, the future looks very hopeful.
#2
Down’s syndrome and stem cells

The original article in this thread describes advances in stem cell treatments for Down’s syndrome. Various studies have recognised that there are stem cells defects in Down’s syndrome. For example, a 2006 study from the Stem Cell Research Group in the Royal Manchester Children’s Hospital in the UK found that there was haematopoietic stem cell deficiency and telomere shortening in Down’s syndrome foetuses and bone marrow from children with Down’s syndrome compared to age-matched healthy controls. This was proposed to be a potentially contributory factor in the susceptibility of Down’s syndrome individuals to leukaemia. Thus studying stem cells and considering stem cell therapy in Down’s syndrome is a rational proposition.

More recent studies from Stanford University School of Medicine and published in the highly influential journal Nature, have identified a gene, Usp16, that could be important in reduction of haematopoietic stem cell renewal in Down’s syndrome. Usp16 is a major deubiquitinase for histone H2A. H2A deubiquitination is important in cell cycle progression and gene expression. The study from Stanford used a mouse model of Down’s syndrome termed Ts65Dn. These mice are trisomic for a portion of chromosome 16 with homology to 132 genes on human chromosome 21. The study showed that trisomy of Usp16 resulted in reduced haematopoietic stem cell renewal, as well as reduced expansion of mammary epithelial cells, neural progenitors and fibroblasts and accelerated fibroblast senescence. The study used both mutation of Usp16 or down-regulation by short interfering RNA to examine whether reduction of Usp16 expression has any effect on these defects; it was confirmed that the defects were improved. In confirmatory experiments in human tissues, it was demonstrated that over-expression of Usp16 abrogated fibroblast and neural progenitor expansion while down-regulation of Usp16 in Down’s syndrome fibroblasts rescued their proliferation defects. Thus Usp16 has been identified as a potential therapeutic target, possibly for gene therapy, for some of the pathologies associated with Down’s syndrome.

Sources

ADORNO, M. et al., 2013. Usp16 contributes to somatic stem-cell defects in Down's syndrome. Nature, 501(7467), pp. 380-384

DE VITA, S. et al., 2010. Trisomic dose of several chromosome 21 genes perturbs haematopoietic stem and progenitor cell differentiation in Down's syndrome. England: Nature Publishing Group.

HOLMES, D.K. et al., 2006. Hematopoietic progenitor cell deficiency in fetuses and children affected by Down's syndrome. Experimental hematology, 34(12), pp. 1611-1615

JOO, H. et al., 2007. Regulation of cell cycle progression and gene expression by H2A deubiquitination. Nature, 449(7165), pp. 1068-1072
  

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Stem Cell Treatments to Relieve Symptoms in Down Syndrome00