Brs Biochem 04/23

Front 1

Set 04 Q: This disorder results from a genetic deficiency of muscle phosphorylase, with accumulation of glycogen in skeletal muscles

Back 1

McArdle Disease (glycogen storage disease) - following exercise, results in painful muscle cramps and weakness due to rhabdomyolysis. Patients may experience bouts of myoglobinuria which can lead to renal failure - cannot break down glycogen

Front 2

Set 04 Q: This disorder results from a deficiency of the glycogen debranching enzyme alpha-1,6-glucosidase

Back 2

Cori Disease (glycogen storage disease) - this leads to accumulation of glycogen in the liver, heart, and skeletal muscles which manifests as stunted growth, hepatomegaly, and hypoglycemia with fasting - can still breakdown linear glycogen - see: hypoglycemia, hypertriglyceridemia, lactic acidosis, hepatomegaly

Front 3

Set 04 Q: This disorder results form a defect in the lysosomal enzyme alpha-1,4-glucosidase, leading to the accumulation of glycogen within the organelle

Back 3

Pompe Disease (glycogen storage disease) - results in accumulation of glycogen in the liver, heart, skeletal muscles. death by age 2 or 3 due to cardiomegaly and heart failure - glycogen accumulates in lysozymes and cannot be broken down

Front 4

Set 04 Q: This disorder results from the autosomal recessive deficiency of glucose 6-phosphatase

Back 4

Von Gierke disease - results from accumulation of glycogen in the liver and kidney and presents with hepatomegaly and hypoglycemia - increase in blood lactate: live can't make glucose and get it out of the cell

Front 5

Set 04 Q: Can result from the autosomal dominant deficiency of the glycolytic enzyme glucokinase, results in severe B cell defects in insulin secretion

Back 5

Maturity onset diabetes of the young (MODY) - other autosomal dominant deficiencies resulting in MODY include mutations in hepatocyte nuclear transcription factor (NHF)-1alpha and HNF-4alpha - glucokinase phosphorylate glucose to keep it in the cell

Front 6

Set 04 Q: This genetic deficiency of a glycolytic enzyme leads to the accumulation of fructose-1-phosphate and inhibition of glucose production

Back 6

Aldolase deficiency (fructose intolerance) - deficiency results in fructose intolerance and life threatening hypoglycemia upon fructose consumption - use all of available phosphate adding to fructose, cannot phosphorylate glucose to keep it in cells - ex: 8 month old pt with liver and kidney problems. Ask parents if child recently started drinking fruit juice

Front 7

Set 04 Q: This mucopolysaccharidosis is due to a deficiency of B-glucuronidase, with accumulation of heparan sulfate, dermatan sulfate, and chondroitin 4,6 sulfate

Back 7

Sly Syndrome - pts present with hepatomegaly, skeletal deformity, and developmental delay. Although experimental, much work has been accomplished in preparing the way for treatment of this disorder with gene therapy.

Front 8

Set 04 Q: This form of mucopolysaccharidosis results from an accumulation of heparin sulfate secondary to a genetic deficiency of heparan sulfamidase, N-acetylglucosaminidase, or N-acetylglucosamine-6-sulfatase

Back 8

Sanfilippo Syndrome - all 3 forms of the syndrome (A,B,C) result from the corresponding enzyme deficiencies; they result in developmental delay, loss of motor skills, and death by second decade of life

Front 9

Set 04 Q: This disorder results from a genetic deficiency of galactose-6-sulfatase, leading to the accumulation of keratin sulfate and condroitin 6-sulfate

Back 9

Morquio Syndrome - unlike other mucopolysaccaridoses, Morquio syndrome is not associated with CNS involvement. - main features: severe skeletal dysplasia, short stature. Motor involvement results from spinal cord impingement on motor neurons

Front 10

Set 04 Q: This glucose transport is the primary transport in hepatocytes. It is insulin-independent and allows the liver to respond appropriately to serum glucose concentrations

Back 10

GLUT-2 - genetic deficiency of this important hepatic transporter results in a type XI glycogen storage disease. Patients present much like those with Von Gierke's disease, with hypoglycemia, ketonuria, and hypercholesterolemia