Mini Portfolio by MARISSA BRADY https://padlet.com/mb0132/q1mqhxuj5q3rieze Common Trait: Intellectual Disabilities en-us 2021-02-27 16:33:45 UTC 2021-03-26 03:15:35 UTC hello@padlet.com Chromosomal Aberration mb0132 https://padlet.com/mb0132/q1mqhxuj5q3rieze/wish/1248407450 Williams Syndrome
Caused by the deletion of 26 genes (including  LIMK1) on chromosome 7
Characterized by problems like cardiovascular disease, developmental delays, and learning challenges
Prevalence of 1 in 7500 live births of any race or gender
The region of chromosome 7 is deleted due to unequal meiotic recombination. One of the genes deleted - LIMK1 - is important in neuronal maturation and migration, thus leading to developmental delays in the brain
There is no treatment for the disorder itself, only treatments for cardiovascular issues that come with it

]]> 2021-02-27 17:03:53 UTC https://padlet.com/mb0132/q1mqhxuj5q3rieze/wish/1248407450 Whole Chromosome mb0132 https://padlet.com/mb0132/q1mqhxuj5q3rieze/wish/1248493530 Trisomy 18 (Edwards Syndrome)
Caused by the presence of an extra chromosome 18
Signs of this disorder are prenatal and postnatal growth deficiency, cognitive disability, cardiac malformations, and surviving youths have severe intellectual disabilities
Overall prevalence is 1 in 2500, but live births with this disorder is 1 in 6000, liveborn females have a higher chance of survival
Due to nondisjunction, the affected individual will either have a full, mosaic, or partial trisomy 18 that interferes with the normal course of development
This disorder is not treatable and can only be helped with supportive medical care]]> 2021-02-27 18:04:17 UTC https://padlet.com/mb0132/q1mqhxuj5q3rieze/wish/1248493530 Single gene mb0132 https://padlet.com/mb0132/q1mqhxuj5q3rieze/wish/1248494111 Tay-Sachs Disease
Caused by autosomal recessive mutations in the HEXA gene on chromosome 15
Becomes apparent in infancy due to loss of motor skills, vision, hearing and/or intellectual disability
In the specific Ashkenazi Jewish population, approximately 1 in 3600 live births is affected
The HEXA gene regulates the production of the enzyme hexosaminidase A, which is necessary to break down the lipid known as GM2-ganglioside. If this isn't broken down, it accumulates in the brain and nerve cells, deteriorating the CNS
There is no effective treatment for this disorder]]> 2021-02-27 18:04:43 UTC https://padlet.com/mb0132/q1mqhxuj5q3rieze/wish/1248494111 Mitochondrial mb0132 https://padlet.com/mb0132/q1mqhxuj5q3rieze/wish/1248502378 Neuropathy, Ataxia, and Retinitis Pigmentosa (NARP)
Caused by mutations in mitochondrial MTATP6 gene
Symptoms include sensory neuropathy, muscle weakness, vision loss, and learning disabilities in children that may develop into dementia in adults
The prevalence is estimated to affect 1 in 40,000 people
The MTATP6 gene forms a part of the enzyme ATP synthase in ATP production. When this gene is mutated it lessens the ability for the mitochondria to make ATP
This disorder is not treatable, but complications from its evolution may be prevented with disease-modifying treatments and consistent follow ups]]> 2021-02-27 18:10:37 UTC https://padlet.com/mb0132/q1mqhxuj5q3rieze/wish/1248502378 Common Trait mb0132 https://padlet.com/mb0132/q1mqhxuj5q3rieze/wish/1248720961 The common trait/symptom that I have chosen to investigate among all of the chosen disorders is a sign of intellectual disability. This can be present in younger children as a developmental delay, or in adults as dementia. I categorized any situation of the symptom in which the affected individual would encounter learning obstacles or would not be able to survive intellectually on their own as an intellectual disability.
Comparing these four cases, the effects of intellectual disability in Williams syndrome and NARP aren't as taxing, presenting more as a developmental and social delay. And the overall disorders themselves are much rarer. But with Trisomy 18 and Tay-Sachs disease, the effects of the intellectual disability are much more taxing and along with the other symptoms, proven fatal early on. ]]> 2021-02-27 20:56:56 UTC https://padlet.com/mb0132/q1mqhxuj5q3rieze/wish/1248720961 Citations mb0132 https://padlet.com/mb0132/q1mqhxuj5q3rieze/wish/1248724739 Cereda, Anna, and John C Carey. “The trisomy 18 syndrome.” Orphanet journal of rare diseases vol. 7 81. 23 Oct. 2012, doi:10.1186/1750-1172-7-81

Gregory, Michael D et al. “Williams syndrome hemideletion and LIMK1 variation both affect dorsal stream functional connectivity.” Brain : a journal of neurology vol. 142,12 (2019): 3963-3974. doi:10.1093/brain/awz323

“Neuropathy, Ataxia, and Retinitis Pigmentosa: MedlinePlus Genetics.” MedlinePlus, U.S. National Library of Medicine, 8 Sept. 2020, medlineplus.gov/genetics/condition/neuropathy-ataxia-and-retinitis-pigmentosa/#frequency. 

Osborne, Lucy R, and Carolyn B Mervis. “Rearrangements of the Williams-Beuren syndrome locus: molecular basis and implications for speech and language development.” Expert reviews in molecular medicine vol. 9,15 1-16. 13 Jun. 2007, doi:10.1017/S146239940700035X

Rawle, Mark J, and A J Larner. “NARP Syndrome: A 20-Year Follow-Up.” Case reports in neurology vol. 5,3 204-7. 19 Dec. 2013, doi:10.1159/000357518

“Tay Sachs Disease.” NORD (National Organization for Rare Disorders), 26 Jan. 2017, rarediseases.org/rare-diseases/tay-sachs-disease/#:~:text=Affected%20Populations&text=Approximately%20one%20in%2030%20Ashkenazi,3%2C600%20live%20births%20is%20affected. 

Vu M, Li R, Baskfield A, Lu B, Farkhondeh A, Gorshkov K, Motabar O, Beers J, Chen G, Zou J, Espejo-Mojica AJ, Rodríguez-López A, Alméciga-Díaz CJ, Barrera LA, Jiang X, Ory DS, Marugan JJ, Zheng W. Neural stem cells for disease modeling and evaluation of therapeutics for Tay-Sachs disease. Orphanet J Rare Dis. 2018 Sep 17;13(1):152. doi: 10.1186/s13023-018-0886-3. PMID: 30220252; PMCID: PMC6139903.
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