Question

In: Biology

Bushy syndrome (BuS), sometimes referred as Amsterdam dwarfism, is a rare human disease caused by a...

Bushy syndrome (BuS), sometimes referred as Amsterdam dwarfism, is a rare human disease caused by a dominant loss-of-function mutation in any one of at least five different genes, all of which encode components or regulators of the cohesin protein complex. People with BuS have a wide range of morphological abnormalities, including growth retardation, mental impairment and sterility. Analysis of BuS patients shows that in addition to chromosomal mis-segregation during cell division, their abnormal phenotype may be likely due to widespread mis-regulation of gene expression during development. Cohesin may play a role in organizing the chromatin loops necessary for proper regulation of transcription. A. (4 points) In different families, BuS can show an autosomal dominant or X-linked dominant inheritance pattern. How is this possible? What is this an example of? B. (4 points) Explain how a loss-of function allele in a gene encoding the cohesin protein could be dominant to the wild-type allele. C. (4 points) BuS is usually caused by new mutation in one parent's genome. Why? D. (3 points) Explain the general function of the cohesin complex in eukaryotic chromosomes. E. (1 Bonus point) What is the role of shugosin?

Solutions

Expert Solution

A) Bushy syndrome appears when at least one of 5 genes get to loose their function. Some of these genes are located in autosomes, while some are located in the X chromosome, that's why sometimes the disease segregates X-linked and sometimes autosomal dominant.

B) This is a rare condition. This happens when the wildtype allele is not capable of giving the needed gene product, cohesin coplex regulator in this case. The lack of a second copy providing of more regulator affects the complex's effectivity, leading to loss-of function of the whole process.

C) The answer of that is the result of discussi 2 different rates: The mutation rates for this regulatory genes, and the reproduction rates for the affected BuS individuals. This could only occur if the mutation rate is higher than the reproductive rate, and that is the case.

D) Cohesin complex has a major role in sister chromatide segregation during cell division. The complex keeps cohesion between the chromatides, ties them together and stabilizes them so the spindle is able to attach to each one of them properly. Once the spindle is attach and ready to pull, the complex degrades.

E) It protects the cohesin complex from degrading too early in the process.


Related Solutions

Bushy syndrome (BuS), sometimes referred as Amsterdam dwarfism, is a a rare human disease caused by...
Bushy syndrome (BuS), sometimes referred as Amsterdam dwarfism, is a a rare human disease caused by a dominant loss of function mutation in any one of at least five different genes, all of which encode components or regulators of the cohesin protein complex. People with BuS have a wide range of morphological abnormalities, including growth retardation, mental impairment and sterility. Analysis of BuS patients shows that in addition to chromosomal mis-segregation during cell division, their abnormal phenotype may be likely...
Cystic fibrosis is a rare disease caused by homozygosity for a recessive allele, and characterized by...
Cystic fibrosis is a rare disease caused by homozygosity for a recessive allele, and characterized by a build-up of mucus in the lungs and difficulty breathing. A woman whose maternal uncle had the disease is trying to determine the probability she and her husband could have an affected child. Her husband's sister died of the disease. Assuming the uncle and the sister are the only family members who had the disease, what is the chance that the couple's first child...
Match the following words to choices below. dwarfism, Addison's disease, Cushing's syndrome, hypoglycemia, type 2 diabetes,...
Match the following words to choices below. dwarfism, Addison's disease, Cushing's syndrome, hypoglycemia, type 2 diabetes, type 1 diabetes 1. increased secretions of cortisol 2. Controlled by a healthy diet and exercise 3. Insulin production decreases or fully stops 4. Increased production of adrenal corticoid hormone 5. Increased production of growth hormone 6. Elevated blood glucose levels
Huntington disease is a rare neurodegenerative human disease determined by an autosomal dominant allele. (Because it...
Huntington disease is a rare neurodegenerative human disease determined by an autosomal dominant allele. (Because it is a rare disease, homozygous individuals are also rare.) The disorder is typically a late onset disease with symptoms appearing after the age of 30. A young man has learned that his father has developed the disease. What is the probability that the young man will also develop the disease? What is the probability that a child of the young man develops the disease?
The Coronavirus disease 2019 (COVID-19) is an infectious disease caused by the severe acute respiratory syndrome...
The Coronavirus disease 2019 (COVID-19) is an infectious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This type of RNA virus causes diseases by replicating only inside the living cells of an organism like mammals and birds. When not inside an infected cell, viruses behave mostly as inert things (e.g., do not self-replicate, do need energy to exist and might crystallize). What traits, common to living things, might define SARS-CoV-2 as a living organism? Define at least...
The human eye disease retinitis pigmentosa is caused by a loss of function mutation (rp) in...
The human eye disease retinitis pigmentosa is caused by a loss of function mutation (rp) in the gene PRPF31. The disease is expressed when combined with wildtype allele 1 (rp+1) in a heterozygote, but not expressed when combined with wildtype allele 2 (rp+2) in a heterozygote. When comparing the number PRPF31 mRNA transcripts in the eyes of rp/rp+1 and rp/rp+2 individuals, researchers have found a higher number of functional PRPF31 mRNAs in the eyes of rp/rp+2 individuals. This is an...
4.Malaria is the deadliest human disease caused by any eukaryote, and as such, malaria parasites have...
4.Malaria is the deadliest human disease caused by any eukaryote, and as such, malaria parasites have profoundly affected human evolution and greatly impact the behaviour of modern humans. a.Consider the allele for haemoglobin S (HbS), which is the altered haemoglobin molecule that results in sickle-cell anaemia when an individual is homozygous for the allele (HbSS).  Why does the allele for HbS persist in populations that live in regions where Plasmodium falciparum is prevalent? Because the Plas b.Which specific protein is at...
Find a human disease that results in dysplasia caused by prolonged chronic inflammation. Discuss the pathophysiology,...
Find a human disease that results in dysplasia caused by prolonged chronic inflammation. Discuss the pathophysiology, symptoms and other abnormalities and treatment (if any).
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT