Fluency- Flashcards
Who are 2 people involved in research behind the cause/ etiology of stuttering?
- Dennis Drayna of NIH and Soo-Eun Chang of Univ of Michigan
What is the relationships between genetics and stuttering?
People who have a genetic link in stuttering causes dysfunction at cellular level
Studies that provide an indication of how hereditary stuttering is
Twin Studies
Can indicate if trait is learned in a family
Adoption studies
Looks at how the disorder occurs in families, the pattern, try to see if a specific gene is at work
Segregation Analysis
A gene-hunting technique that traces patterns of disease in high-risk families. It attempts to locate a disease-causing gene by identifying genetic markers of known chromosomal location that are co-inherited with the trait of interest.
Linkage studies
Twin studies showed consistency between monozygotic (identical) twins ranged from __ to __ %
20-90%
For dizygotic (fraternal) twins, they were consistent in __ to __%
3-19%
Why is heritability not 100% in identical twins?
Environmental factors (epigenetics) can affect it, as well as temperment
Why is stuttering more common in men than women?
Women have been shown to have a higher “genetic threshold” & require more “susceptibility alleles” to stutter than men (Kidd, et al 1978
What is the Lysosome?
The “garbage disposal” of the cell
Special place in the cell because it plays a role in cell degradation
Contain enzymes that break down carbs, lipids, proteins, acids, & debris
Contain enzymes (~50) that break down the waste.
When a cell goes through recycling, it needs a lot of enzymes in the lysosome
The lysosomal targeting pathway is the process of getting the enzymes to the lysosome.
What happens in the lysosomal targeting pathway process?
is the process of getting the enzymes to the lysosome. GNPTAB/G- enzyme that leads all the other enzymes to the lysosome
As enzymes try to enter lysosome, there is a special “uncovering” enzyme called NAGPA. NAGPA is the signal that tells the cells that this enzyme needs to go through some other compartments in the cell, then go to the lysosome
What disease is a rare genetic disorder passed from parents to child. It’s caused by the absence of an enzyme that helps break down fatty substances?
Tay-Sachs (lysosomal storage issues)
Mutations found in 3 genes (and possibly a 4th) accounted for up to 20% of familial stuttering.
- GNPTAB
- GNPTAG
- NAGPA
- AP-4
Breaking Research in 2020 (Dr. Tae-Un Han, NIH) showed
abnormal brain cell types- astrocytes. Prominent abnormality in the corpus collosum, Ultimately understanding stuttering at a cellular level may help in course of treatment (pharmacology).
