An 18-month-old girl is brought to the pediatrician’s office for failure to thrive and developmental delay. The patient’s mother says she has not started speaking and is just now starting to pull herself up to standing position. Furthermore, her movement appears to be restricted. Physical examination reveals coarse facial features and restricted joint mobility. Laboratory studies show increased plasma levels of several enzymes. Which of the following is the underlying biochemical defect in this patient?
ACongenital lack of lysosomal formation
BInappropriate protein targeting to endoplasmic reticulum
CFailure of mannose phosphorylation
DInappropriate degradation of lysosomal enzymes
EMisfolding of nuclear proteins
An investigator is studying the function of the endoplasmic reticulum in genetically modified lymphocytes. A gene is removed that facilitates the binding of ribosomes to the endoplasmic reticulum. Which of the following processes is most likely to be impaired as a result of this genetic modification?
AProduction of secretory proteins
BNeutralization of toxins
CUbiquitination of proteins
Dα-Oxidation of fatty acids
ESynthesis of ketone bodies
A genetic population study is being conducted to find the penetrance of a certain disease. This disease is associated with impaired iron metabolism and primarily affects the liver. Patients often present with diabetes and bronze skin pigmentation. After a genetic screening of 120 inhabitants with a family history of this disease, 40 were found to have the disease-producing genotype, but only 10 presented with symptoms. What are the chances of the screened patients with said genotype developing the disease phenotype?
A0.4%
B40%
C3%
D4%
E25%
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