Mod 5 Exam 4 Flashcards
Insertion mutation
Adds one or more extra nucleotides into DNA seq - alters the reading frame
Autosomal dominant
Non-sex linked disorder mediated by the dominant allele
Autosomal recessive
Non-sex linked disorder mediated by recessive allele
X-linked recessive
Sex linked disorder caused by recessive allele on the X chromosome. You need both recessive alleles in females, only need one in males
Marfan’s syndrome - type and cause
Autosomal dominant. Missense mutation of Fibrillin-1. FBN1 is an essential glycoprotein in ECM and in prod/ maint. of elastic fibers (abundant in eye, ligaments and aorta). Mutant FBN1 can’t sequester TGF-B which is important for growth factors.
Sickle Cell Anemia - Type and cause
Autosomal recessive. Missense mutation in B-Globin on hemoglobin. Cuases RBC to become rigid, and sickle shaped. Cause ischemia, vessel occlusion. They deplete fast - anemia.
Sickle Cell Anemia - S/ S
Low RBC count, extreme fatigue, Crises (chest, abdomen and joint pain from ischemia), edema, risk of stroke and acute chest syndrome.
Sickle Cell Anemia - protective factor?
People who are heterozygous (Aa) have both normal and sickle shaped RBC (Co-dominance). They are protected from malaria, but aa and AA are not.
Spinal muscle atrophy - type and cause
Autosomal recessive, SMN1 gene. Affects the anterior horn/ motor neurons.
Spinal muscle atrophy - S/ S
Progressive muscle wasting and mobility impairment; starting from proximal muscles of arms and legs.
Rett Syndrome - S/ S
Delayed growth, loss of movement and coordination, loss of communication abilities, hand tapping, unusual eye movements, agitation, cognitive disability, seizures, scoliosis, pain
Protanopia
Dichromacy, lack red cones - can’t see red
Deuteranopia
Lack green cones - can’t see green
Protanomaly
Mutated form of red pigment in cones
Deuteranomaly
Mutated form of the green pigment in cones. Most common type of colour blindness.
Muscular dystrophy - type and cause
X linked recessive. 2 types, affects dystrophin. D links the actin cytoskeleton to ECM. Without it the sarcolemma collapses, allows Ca in, water follows into the cell/ mitochondria - muscle cell death.
Becker’s muscular dystrophy
Misshapen dystrophin, less severe, life expectancy 45 yo.
Muscular dystrophy - S/ S
Progressive muscle weakness (esp in legs), psudohypertrophy of calfs, wheel-chair bound, resp disease, scoliosis, cardio myopathies, arrythmias.
Down Syndrome
Trisomy of Chromosome 21, Robertsonian translocation. Inc risk to do with maternal age.
Robertsonian translocation
Occurs in Down Syndrome. Long piece of Chr 21 breaks off and attaches to 14. So you end up with two normal chromosome 21 and one extra attached to 14.
Prader-Willi Syndrome
Monosomy of Chromosome 15. Mild to moderate intellectual disability, increase appetite (elevated ghrelin), leads to Type II diabetes, behav problems (ADD< ADHD), infertility.
Angelman Syndrome
Deletion or inactivation of genes on maternally inherited chromosome 15. Severe intellectual and dev disability, speech impairment, sleep disorders, seizures, balance and movement problems (hand flapping), frequent laughing, smiling and happy demeanor.
Klinefelter syndrome
47XXY - nondysjunction of sex chromosomes in meiosis I. Risk inc with old mother. Noticed around puberty, infertility, taller height, less body hair, small testes, gynecomastia (dev od breast tissue) and low libido, normal intelligence.
Pregnancy
Fertilization to birth. Typically 40 weeks, from the first day of the last menstrual cycle
