Genetic and Pediatric Diseases Flashcards
What is the difference among genetic diseases, hereditary diseases, and congenital disorders?
Genetic diseases are due to permanent DNA changes - can be due to somatic DNA mutations.
Hereditary diseases are derived from germline DNA.
Congenital disorders might not be genetic.
Are all genetic disorders present in infancy and childhood?
Are all pediatric diseases of genetic origin?
Nope, nope.
Do autosomal dominant and recessive disorders manifest equally between both sexes?
yeah
What is the pattern of inheritance of Marfan’s syndrome? Can the mutation be sporadic? Does it exhibit variable expressivity?
Autosomal dominant.
1/3 of cases are from sporadic mutations.
Yeah variable expressivity; manifests through a variety of abnormalities (pleiotropy).
What is the subcellular etiology of Marfan’s syndrome? What organs can be affected?
Fibrillin-1 mutation: messed up fibrillin, which links elastin together in CT.
Affects the heart, aorta, skeleton, ligaments, eyes (ciliary zonules of the lens are suspended by fibrillin), and skin.
The fibrillin-1 gene is located on chromosome _____ and there are more than ______ different distinct mutations affecting the gene.
chromosome 15, more than 600 mutations that affect the gene
What are the clinical features of Marfan’s syndrome (7)?
- Tall, long legs.
- Long extremities and fingers (arachnodactyly - spider fingers).
- Long skull.
- Deformed chest.
- Weak tendons, ligaments, joints –> hyperflexible joints, dislocations.
- Hernias
- Kyphoscoliosis
Specifically how does Marfan’s syndrome affect the aorta and heart?
Tunica media of the aorta is weakened due to fragmented elastic fibers –> predisposition to dissecting aneurysm.
Heart valves are floppy, especially the mitral.
What is the leading cause of death in the case of Marfan’s syndrome?
cardiovascular disorders
Specifically how does Marfan’s syndrome affect the eyes (3)?
- Dislocation of the lens
- Severe myopia
- Retinal detachment
Consanguineous marriage increases the incidence of ________ ________ disorders.
autosomal recessive
Autosomal recessive disorders usually affect enzyme proteins, while autosomal dominant disorders often affect….(2).
Autosomal dominant disorders usually affect structural components such cytoskeletal proteins (collagen) and regulatory proteins in complex metabolic pathways.
What is the pattern of inheritance of cystic fibrosis?
Autosomal recessive
CF is a widespread disorder of ________ ________ affecting fluid secretion in exocrine glands and the epithelial lining of the _________, _________ and __________ tracts.
disorder of epithelial transport
affects respiratory, gastrointestinal, and reproductive tracts
Name the disease: abnormally thick mucus that obstructs the lumina of airways, pancreatic and biliary ducts, as well as the fetal intestine, and impairs airway mucociliary function.
Cystic fibrosis
What is the most common lethal autosomal recessive diseases in caucasians?
Cystic fibrosis
CF patients have chronic ________ disease, deficient ________ pancreatic function, and other complications of thickened _______ in the small intestine, liver, and reproductive tract
chronic pulmonary disease, deficient exocrine pancreatic function, complications of thickened mucus in the small intestine, liver, and reproductive tract
What is the most common genetic defect involved in CF? What does the gene product do in sweat glands and respiratory epithelium?
Mutation of the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) on chromosome 7.
In sweat glands, the CFTR protein normally pulls Cl- out of sweat (and Na+ follows) - which is why the sweat is so salty.
In respiratory epithelium the CFTR protein normally pumps Cl- INTO mucus - sets up osmotic gradient for H2O to follow. This is why mucus is so thick.
More than 1,300 CFTR mutations have been identified and 1 in ___ Caucasians are carriers. Incidence is 1 in ______ in Caucasian newborns.
1 in 25 are carriers
1 in 3,200 incidence
