Enzyme Deficiencies Flashcards
Pompe disease
Def: acid alpha glucosidase
Can’t break down glycogen properly
AR. muscle weakness, cardiomyopathy, hepatomegaly.
Treatment: Gene or enzyme therapy
Galactosemia
Def: Galactose 1-p uridyltransferase (converts galactose 1-p to UDP-galactose)
Accumulation of galactose which is toxic to tissues. Diarrhea, vomiting, jaundice
AR
Treatment: Galactose free diet supplement with vit. D and calcium.
Hereditary Fructose Intolerance
Def: Aldolase B (convert fructose 1-p to Glyceraldehyde 3 phosphate and dihydroxyacetone P)
A part of glycolysis
AR. Accumulation of fructose 1-p and so hypoglycemia, jaundice, hepatomegaly, vomitting
Treatment: low fructose diet
Glucose-6-phosphate Dehydrogenase Deficiency
Def: G-6-p Dehydrogenase
(converts G-6-P to 6-phosphoglucano delta lactone)
a part of pentose phosphate pathway
X-linked Recessive (more males get it). Oxidative stress causes burst in RBCs, anemia, jaundice
Treatment: Avoid fava beans, oxidative agents like drugs. Blood transfusion
Medium chain Acyl Coa Dehydrogenase Deficiency
Def: Medium chain Acyl coa Dehydrogenase Deficiency
(converts fatty acids and coenzyme A to acyl CoA) a part of beta oxidation.
AR. Can’t break down medium chain FA so hepatomegaly, no gluconeogenesis
Treatment: glucose or simple sugars
Zellweger Syndrome
Issue: No peroxisomes. Myelin can’t break down in the CNS so accumulation of VLFA
AR. Seizure. Loss of vision, sensation. poor feeding. developmental delay
Has infantile, childhood and adolescent forms. Worst is in childhood.
Treatment: Treatment of symptoms. MRI of the brain, liver function, monitor cognitive and motor function.
Tay-Sachs disease
Def: beta-N-acetylhexaminidase A
Break down of sphingolipids is messed up. Accumulation of gangliosides. More common in Jews and French Canadians.
AR
Motor dysfunction and hearing loss
Gaucher disease
Def: glucocerebrosidase
AR
Issues with platelets like bruising easy, anemia, hepatomegaly, neurological complications.
Treatment: gene therapy
Fabry disease
Def: alpha galactosidase A
XR (more males get it )
Pain in the hands and feet. Angiokeratomas, decreased sweating. Kidney issues.
Treatment: pain management, ACE inhibitors for proteinuria, renal transplant
Hurler syndrome( MPS I)
Def: alpha-L-iduronidase
AR. Problem with breaking down glycosaminoglycans in the lysosome. They build up in organs. Large birth weights, hernia, microcephalic, hydrocephaly, intellectual disability.
Treatment: sunglasses to reduce glare or correction surgery.
I-cell Disease (ML II)
Def: N-acetyl glucosamine-1-p transferase
aka inclusion cell disease
AR- developmental delay, skeletal abnormalities, restricted joint movement, enlarged organs.
Treat the symptoms and give iron and B12
Lesch-Nyhan Syndrome (LNS)
Def: HGPRT
so salvaging hypoxanthine and guanine
XR- (more males get it)
self harm, neurological dysfunction, hematuria, sand llike crystals in diaper, juvenile gout, uric acid build up and kidney stones
Treatment: Allopurinol for gout, lithotripsy for kidney stones
Acute intermittent Porphyria
Def: prophobilinogen deaminase (aka hydroxymethylbilane synthase).
AD. abdominal pain, neuropsyc issues, dark urine
Treatment: high carbs, opiates for pain.
Gilbert Syndrome
Def: bilirubin uridine diphosphate glucuronosyltransferase
AR. increased unconjugated bilirubin. jaundice that happens with stress (dehydration, fasting, illness, crazy exercise, menstruation)
Crigler-Najjar Syndrome Type I
Def: Complete absence of the enzyme (bilirubin uridine diphosphate glucuronosyltransferase)
AR. increased unconjugated bilirubin
jaundice with stress (dehydration, fasting, illness, crazy exercise, menstruation)
Treatment: phototherapy, exchange transfusion, liver transplantation
Crigler-Najjar Syndrome Type II
Def: Partial absence of the enzyme (bilirubin uridine diphosphate glucuronosyltransferase)
similar to Gilbert Syndrome.
AD. increased unconjugated bilirubin. Jaundice with stress (dehydration, fasting, illness, crazy exercise, menstruation)
Treatment: Phenobarbital
Dubin-Johnson Syndrome
Def: Multidruug resistant protein 2
AR. Issue with transfering bilirubin out of the liver. more common in Iranians,and Morocon jews
Jaundice due to conjugated bilirubin build up, dark liver
Treatment: nothing necessary.
Rotor Syndrome
Def: Solute carrier organic anion transporter
AR. Issue with transferring the bilirubin out of the liver
Jaundice to to conjugated bilirubin.
Treatment: no treatment necessary
PKU
Def: phenylalanine hydroxylase (converts phenylalanine to tyrosine)
AR. Dark urine, musty smell, intellectual disabilities.
Treatment: Tyrosine supplement, low protein diet.
ornithine transcarbamylase deficiency
Def: ornithine transcarbamylase (converts ornithine to citrulline)
X-linke R. This is the beginning of the urea cycle so ammonia build up and its toxic for the brain. Seizures, neuropsyc issues.
Treatment: Arginine supplement, sodium benzoate to scaveneg nitrogen
Tyrosinemia I
Def: fumaryacetoacetate hydroxylase (breaks down tyrosine)
AR. Tyrosine builds up which is toxic for the liver. Rancid butter/cabbage smell of urine
Treatment: low tyrosine diet
Alkaptonuria
Def: homogentisate 1,2-dioxidase
AR. Can’t break down tyrosine. pain in joints, black cartilage and black urine. excess homogentisitic acid turns into benzoquinone acetic acid which deposits into the collagen making it black and stiff.
Treat: low tyrosine and phenylalanine dier. joint replacement
Homocystinuria
Def: CBS (cystathionine beta-synthase which converts homocystein and serine into cysteine)
AR. homocystein and methionine in the urine. myopia, dislocation of the lens, brittle bones, abnormal blood clots
Treat: pyridoxine and folic acid.
Maple syrup urine
Issue is breaking down branched AA
AR. Build up of branched AA which is toxic to the brain, maple syrup smell of the urine and ear wax
Treat: Avoid branched AA in diet (valine, leucine and isoleucine)
