malignant phenylketonuria
what enzyme is absent?
why malignant?
complication?dihydrobiopterin redactase(catalyze the production of tetrahydrobiopterin(BH4))
refractory to tyrosine supplement
(treatment: BH4 supplementation, low phenylalanine diet)
alkaptonuria
what enzyme is absent? in which pathway?
findingshomogentisate oxidase
(catalyze the production of ¥maleylacetoacetic acid from homogentisic acid)
cystic fibrosis
mutation,diagnosis,complications,treatmentCFTR gene on chromosome 7
autosomal recessive
(CTFR codes Cl-channel secreting Cl in lung and GI tract, reabsorbing Cl in sweat glands)
☆misfolded CFTR membrane protein
↑Cl concentiation in pilocarpine induced sweat test
recurrent pulmonary infection,pancreatic insufficiency→malabsorption with steatorrhea(fat containing stool),meconium ileus in newborn,infertility,nasal polyps,digital clubbing
how Vit B12 is bound to intrinsic factorPancreatic proteases are secreted into the duodenum, where they split the R-protein/vitamin B12 complexes, producing vitamin B12 that is free to bind intrinsic factor to form intrinsic factor/vitamin B12 complexes. biochemistrygastrointestinal HirotoShishido
