Questions for Paper 1:
Marfan Syndrome
1. What is the species that your condition affects? Introduce your species – tell me something about it such as its common name, where it lives, how it reproduces, etc. - Species: Homo Sapiens - Common Name: Humans - Where it lives: Earth - How it reproduces: SEX
2. What is your genetic condition? Introduce the name of the condition, what this means phenotypically for a patient with this condition, etc. - Name: Marfan Syndrome - Phenotypically: - Arm span exceeding height - Nearsightedness -Thin, Narrow Face - Sunken or protruding chest - Arachnodactyly fingers and toes (long, slender, and curved) - Scoliosis >20º - Dilation of the aorta - Aortic Dissection (Separation of aorta walls) - Ectopia lentis (Displacement of eye's crystalline lens from its normal location)
3. How is this condition acquired (i.e. single base mutation during DNA replication, deletion, insertion, chromosomal aberration, etc.)? - How it is acquired: - Mutation of the FBN1 gene (fibrillin 1)
a. Explain this in the context of cell division, mitosis/ meiosis – which is cell cycle is affect, how, when, etc. -Mutations change a single protein building block (amino acid) in the fibrillin 1 protein -FBN1 mutations that cause Marfan Syndrome reduce the amount of fibrillin 1 produced by the cell, alter the structure or stability of fibrillin 1, or impair the transport of fibrillin 1 out of the cell - The mutations lead to a severe reduction of the amount of fibrillin 1 available to form microfibrils -Without enough microfibrils, excess growth factors are activated and elasticity of many tissues is decreased, leading to overgrowth and instability of tissues and lead to signs of Marfan Syndrome 4. Is your genetic condition inheritable? If so, how (i.e. autosomal, sex-linked, dominant,