Human Genetics 29

Students should ensure to watch the posted video.
Grades on D2L: Students can view their grades with and without an exam drop in the grade book.
Grades are calculated in Excel, all assignments will be graded, and students will receive credit for completed work.
Students are encouraged to communicate only about grade inconsistencies rather than requesting higher grades.
Points left in the class: Approximately 220 points plus additional points from undetermined assignments mean students can still significantly raise their grades.

Students should check the course progress feature visible in D2L to ascertain potential highest and lowest grades based on performance.
There is a total of nearly 300 points remaining for further improvement throughout the semester.

Focus of Chapter 12: Review mutations and their implications as well as implications for upcoming exams.
Transition to Next Chapters: Following chapter 12, chapters 15, 16, and 17 will cover Hardy-Weinberg principles and genetic testing, and will be the focus of Exam 5 during finals week.
Further discussions are planned on these chapters starting Monday.

Familial Hypercholesterolemia:    - Involving mutations in the LDL receptor gene, which regulates lipid amounts in cells.    - Wild Type Structure: Illustrated as a membrane protein with specific charges on amino acids.    - Examples of mutations:
     - Missense Mutation: Affects protein function by changing an amino acid.
     - Nonsense Mutation: Introduces an early stop codon, resulting in premature termination of the protein synthesis.      - Frameshift Mutation: Caused by insertions or deletions of nucleotides affecting the reading frame of mRNA during translation.    - Key Takeaway: A single amino acid change can impact health
Triplet Repeat Diseases:
- Example: Huntington's Disease - caused by repeated CAG sequences in the Huntington gene. - Normal allele: typically less than 35 repeats, expanded sequences during DNA replication can reach up to 90-120 repeats leading to disease. - Phenotype severity and onset: Earlier onset and more severe symptoms correlate with increased repeat counts. - Inheritance Pattern: Autosomal Dominant - only one abnormal copy required for disease expression leading to neuronal degeneration. - Myotonic Dystrophy: Differences found in non-coding sequences causing disrupted gene expression and muscle disorders.

Anticipation: Refers to the phenomenon where repeat expansions in genetic sequences increase in severity across generations.
Copy Number Variants (CNVs): Variations in the number of copies of particular DNA segments that can be used in genetic testing.
Short Tandem Repeats (STRs): Variations in repeat sequences on chromosomes that are often used in paternity testing and genetic profiling.
Polymerase Chain Reaction (PCR): A laboratory technique used to amplify DNA sequences for analysis based on the number of repeat copies present.

Analyzing individuals via gel electrophoresis to differentiate repeat lengths (e.g., bands of 20 base pairs vs. 12 base pairs) helps determine parental relationships or potential crime scene investigations.

Sickle Cell Mutation: Provides an advantage against malaria for heterozygous carriers, highlighting the evolutionary impact of mutations in different environments.
Discussion on hemoglobin mutations and their variable effects on phenotype, including silent mutations where an amino acid remains unchanged despite nucleotide changes.
The course will continue with Hemoglobin mutations in the upcoming sessions.

Students are encouraged to finish their readings and complete any outstanding work before Monday's class where further topics will be covered.
Questions and discussions are welcomed to ensure comprehension though frustrations with past educational experiences were humorously shared for relatability.
Final note: Stay engaged as many critical topics will be discussed in the following classes, and preparation is key for success in upcoming assessments.