Disorders with Atypical Pattern of Inheritance - Single Gene Disorders 2
Dr. Yakubovskyy - March 19, 2012
Semester 4, Mini 3
6 month old infant presents severe mental retardation and hypopigmentation. In your investigations you find that there are high levels of serum phenylalanine. What disease do you suspect? What enzyme is defective? What is the associated inheritance pattern?
PKU → phenylalanine hydroxylase → AR
What amino acid becomes essential in PKU?
6 month old infant presents severe mental retardation and a mousy urine smell. What is the disease? What makes the smell mousy?
PKU → accumulation of phenylacetic acid
What test is used to screen newborns for PKU?
heel prick test
What is the tx for pts diagnosed with PKU?
Phenylalanine restriction in the diet starting from postnatal period Expectant mothers homozygous for PKU: low-phenylalanine diet
What is the enzyme deficient in galactosemia? As a result, what accumulates?
Infant presents with failure to thrive with vomiting and diarrhea following milk ingestion. He also appears jaundice with hepatomegaly. Within a few weeks he develops cataracts. What is your likely dx?
What type of bacterial septicemia are galactosemia pts at risk for?
E. coli septicemia
What cells are tested for GALT activity in the dx of galactosemia?
What is the tx of galactosemia?
milk free diet
What chromosome is the CFTR gene on?
What channel does CFTR inhibit?
How does a mutated CFTR gene effect mucous viscosity?
↑ mucous viscosity
How does a mutated CFTR channel lead to pancreatic duct plugging?