Down Syndrome by Sasha Bilodeau

Down Syndrome

sashalb093 — 2024-04-03 16:03:23 UTC

Down Syndrome is a genetic condition where a person is born with an extra copy of chromosome 21 which gives them a total of 47 chromosomes instead of the normal 46. It can result from trisomy 21, translocation, or mosaicism. Trisomy 21 is the most common with the extra copy of chromosome 21. Translocation occurs when there’s a partial or full amount of chromosome 21 attached to another chromosome. Mosaicism occurs when some cells contain the 46 chromosomes, and some the 47 with the extra chromosome 21. Mosaicism is the rarest, occurring in less than 1% of Down syndrome cases.

sashalb093 — 2024-04-03 16:32:34 UTC

Importance of Understanding

sashalb093 — 2024-04-03 16:40:27 UTC

Since the disorder is the most common chromosomal-related condition, it is important to be familiar with the symptoms one can expect as well as the resources available to live their lives to the fullest.

Cause of the disorder

sashalb093 — 2024-04-03 16:41:19 UTC

It is believed that women who are older than 35 are more likely to have a child diagnosed with down syndrome, however, the most babies born with the disorder are to women under 35. In a study conducted by Molteni (2022), twins were compared since one had down syndrome while the other did not. Senescent cells were discovered in the twin with down syndrome which are also found in diseases of aging. Senescent cells lose their ability to divide and secrete cytokines. These components tag the cells for destruction by the immune system and causes inflammation. The cells also become compact and end up altering the types of genes the cells express.

Testing/ Treatment

sashalb093 — 2024-04-03 16:42:01 UTC

· Ultrasound

· Amniocentesis

· Chorionic Villus Sampling

· Percutaneous umbilical blood sampling

· Karyotype test

· PT/OT

· Speech therapy

· Special education programs

· Treating underlying medical conditions

· Glasses/ hearing devices

sashalb093 — 2024-04-03 16:44:10 UTC

Down syndrome is the most common chromosome-related condition with 1 in every 700 births resulting in the syndrome.

Symptoms & Life Expectancy

sashalb093 — 2024-04-03 21:10:10 UTC

Some physical signs of Down syndrome include a flat nose bridge, slanted eyes, a short neck, small ears, hands, and feet, shorter-than-average height, and a single palmar crease. Children may have intellectual or cognitive disabilities which can delay developmental milestones. They may also have behavioral symptoms such as tantrums, difficulty with focus, and obsessive-compulsive tendencies. The disorder can affect anyone, happens randomly, and is not a result of anything the parents did before or during the pregnancy. The life expectancy of a person diagnosed with Down syndrome is 60 or older, but they may require support and care throughout their entire life depending on their abilities.

In Vitro Success in Removing or Silencing the Extra Chromosome

sashalb093 — 2024-04-05 01:53:23 UTC

· Introduction of a TKNEO gene carried by a modified adenovirus to the gene amyloid-beta precursor protein resulted in a spontaneous loss of the extra copy of chromosome 21. No other chromosomes were affected by this procedure.

· X-inactive specific transcript inactivates the DNA of the extra chromosome through methylation and chromatin modification. No other chromosomes were affected by this procedure.

· Chromosome correction through blastomere biopsy and genetic analysis prior to implantation in the uterus. Legislations in most countries do not authorize research on human embryos and embryonic stem cells since they result in destruction of the embryos. However, Yamanaka developed iPSC which is a technique that does not destroy the embryos.

References

sashalb093 — 2024-04-05 02:09:43 UTC

Asim, A., Kumar, A., Muthuswamy, S., Jain, S., & Agarwal, S. (2015). “Down syndrome: an insight of the disease.” Journal of Biomedical Science, 22(1), 41–41. https://doi.org/10.1186/s12929-015-0138-y

Cleveland Clinic. (2023). Down Syndrome. Accessed on March 11, 2024, from https://my.clevelandclinic.org/health/diseases/17818-down-syndrome

Molteni, M. (2022). Provocative new findings suggest a surprising cause of Down syndrome: cells linked to aging. STAT.

Rondal, J. A. (2021). From the lab to the people: major challenges in the biological treatment of Down syndrome Running title: Biological treatment of Down syndrome. AIMS Neuroscience, 8(2), 284–294.

Van Herwegen, J., Ashworth, M., & Palikara, O. (2018). Parental views on special educational needs provision: Cross-syndrome comparisons in Williams Syndrome, Down Syndrome, and Autism Spectrum Disorders. Research in Developmental Disabilities, 80, 102–111. https://doi.org/10.1016/j.ridd.2018.06.014

Linked to Diseases of Aging

sashalb093 — 2024-04-05 02:26:33 UTC

· Senescence could play a role in the neuropathy of Down Syndrome according to a study by Hiruy Meharena

· Senescence is a natural stress response where cells lose their ability to divide. It prevents old cells from proliferating and causing cancer. They secrete cytokines that accumulate causing systemic inflammation. The cells undergo changes including the collapse and compaction of chromosomes and the altering of the types of genes the cells express.

· In people with Down Syndrome, there is an overcrowding due to the extra chromosome which prompts a reorganization of the entire genome of the developing brain.

· Meharena identified that senescence is a potential driver for the neurodevelopmental abnormalities in Down Syndrome.