In this genotype, the most notable chromosome would be the 21st. Chromosome 21 is a very small chromosome, one of the smallest in fact. Despite this, two prominent syndromes are related to genes on it; Alzheimer’s disease and down syndrome, both causing intellectual impediments. Alzheimer’s causes dementia and its effects worsen over time, while down syndrome causes delays in physical and mental growth.
As I said, chromosome 21 is one of the smallest chromosomes in the human body and represents approximately 1.5% of the DNA in cells. It was also the second human chromosome to be fully sequenced, after chromosome 22. Some of the genes located on chromosome 21 include APP, CBS, and HLCS; which stands for amyloid beta precursor protein, cystathionine-beta-synthase, and holocarboxylase synthetase, respectively. These, and other genes, are typically related to proteins and enzymes. One of these, DSCR1, is typically overexpressed in the brains of children with down syndrome and can lead to neurofibrillary tangles, such as those associated with Alzheimer’s disease. …show more content…
The first is Alzheimer’s disease, which typically becomes prominent in older stages of life. It is a chronic neurodegenerative disease and causes the majority of cases of dementia, meaning memory loss and other intellectual disabilities. As a neurodegenerative disease, its symptoms becomes worse over time. Despite it having no cure, the symptoms can be slowed with medicine. The second of the two is down syndrome, also known as trisomy 21. It is caused by having three copies of chromosome 21, which is also known as a trisomy; hence the name “trisomy 21”. In the genotype given here, there is a case of trisomy
As I said, chromosome 21 is one of the smallest chromosomes in the human body and represents approximately 1.5% of the DNA in cells. It was also the second human chromosome to be fully sequenced, after chromosome 22. Some of the genes located on chromosome 21 include APP, CBS, and HLCS; which stands for amyloid beta precursor protein, cystathionine-beta-synthase, and holocarboxylase synthetase, respectively. These, and other genes, are typically related to proteins and enzymes. One of these, DSCR1, is typically overexpressed in the brains of children with down syndrome and can lead to neurofibrillary tangles, such as those associated with Alzheimer’s disease. …show more content…
The first is Alzheimer’s disease, which typically becomes prominent in older stages of life. It is a chronic neurodegenerative disease and causes the majority of cases of dementia, meaning memory loss and other intellectual disabilities. As a neurodegenerative disease, its symptoms becomes worse over time. Despite it having no cure, the symptoms can be slowed with medicine. The second of the two is down syndrome, also known as trisomy 21. It is caused by having three copies of chromosome 21, which is also known as a trisomy; hence the name “trisomy 21”. In the genotype given here, there is a case of trisomy