Metabolic Medicine

Question 1

Which condition is associated with sweaty feet odour?

Answer 1

Isovalaeric Acidaemia

Question 2

What is the investigation of choice for isovalaeric academia?

Answer 2

Urine organic acids showing elevated C5 acylcarnitine

Question 3

Which condition is associated with a sweet smell to ear wax/ urine?

Answer 3

Maple syrup urine disease

Question 4

How is MSUD diagnosed?

Answer 4

Detection of L-alloisoleucine

Question 5

What is the management of MSUD?

Answer 5

Leucine, isoleucine and valine

Question 6

Which condition is associated with a musty smell?

Answer 6

PKU

Question 7

What are the symptoms of PKU?

Answer 7

Fair hair
Blue eyes
Eczema
Photophobia
Microcephaly
Intellectual disability
Epilepsy

Question 8

What is the pathophysiology of PKU?

Answer 8

A deficiency in phenylalanine hydroxyalase causes elevated levels of phenylalanine

Low tyrosine levels also lead to low dopamine and epinephrine levels

Question 9

How is PKU diagnosed?

Answer 9

Plasma amino acids
Elevated phenylalanine levels

Question 10

How is PKU managed?

Answer 10

Commence low protein diet
Phenylalanine free medical formula - should be mostly breast fed as this is naturally low in phenylalanine (e.g. XP Analog LCP)

Avoid aspartame’s

Question 11

What are the features of homocystinuria?

Answer 11

Tall stature
Intellectual disability
Ectopia lentísimo (downward dislocation of the lens)
Osteoporosis
Recurrent thrombosis

Question 12

What is the pathophysiology of homocystinuria?

Answer 12

Due to a deficiency of cystathionine beta-synthase

Question 13

How is homocysteine diagnosed?

Answer 13

Elevated methionine
Elevated homocysteine levels

Question 14

How is homocysteine diagnosed?

Answer 14

High dose pyridoxine

Question 15

What differentiates homocystinuria from marfan syndrome?

Answer 15

Autosomal recessive
IQ down
Lens dislocation down

Question 16

What differentiates Marfan syndrome from homocystinuria?

Answer 16

Autosomal dominant
IQ up
Lens dislocation up

Question 17

What condition is associated with black urine?

Answer 17

Alkaptonuria

Question 18

How is alkaptonuria diagnosed?

Answer 18

Homogentisic acid in urine

Question 19

Features include failure to thrive, hepatomegaly, renal tubular acidosis (Fanconi syndrome) and radiographic fraying of rickets?

Answer 19

Tyrosinaemia type 1

aka hepatorenal tyrosinaemia

Question 20

How is tyrosinaemia diagnosed?

Answer 20

Elevated plasma and urine succinylacetone levels

Question 21

What are the key findings of urea cycle disorders?

Answer 21

Very high ammonia (>1000)
Respiratory alkalosis

Question 22

What are the laboratory findings in MCAD?

Answer 22

Hypoketotic hypoglycaemia
Hyperammonaemia
Elevated C6, C8 and C10 carnitine esters on plasma acylcarnitine profile

Question 23

Which condition can present with cataracts and hypoglycaemia?

Answer 23

Galactosaemia

Question 24

What are the features of galacetosaemia?

Answer 24

Cataracts
Hypoglycaemia
Vitreous haemorrhage
Jaundice
Hepatosplenomegaly

Question 25

Which condition presents with positive urine reducing substances?

Answer 25

Galacetosaemia

Question 26

What is a the possible complications of galactosaemia?

Answer 26

E. coli sepsis Ovarian failure Amenorrhoea

Question 27

What are the features of Pompe disease?

Answer 27

Muscle wasting Cardiomegaly Macroglossia

Question 28

What is the pathophysiology of McArdle Disease?

Answer 28

Deficiency of muscle phosphorylase which is required in the conversion of glycogen to glucose Hence a lack of glucose in the muscle causes pain or cramps on exercising

Question 29

What are the features of McArdle disease?

Answer 29

Exercise induced cramps/ exercise intolerance Can cause rhabdomyolysis Elevated CK levels at rest

Question 30

Which condition should be considered in infants who are given juice/ fruit for the first time?

Answer 30

Fructose 1, 6 diphosphate deficiency

Question 31

What are the features of mucopolysaccharidoses?

Answer 31

Initially appear normal however with the accumulation of mucopolysaccharides the patient develops: Coarse facial features Organomegaly Bony deformities Developmental regression Sensory loss (hearing and vision)

Question 32

What do the eyes appear like in Hurler Syndrome (MPS type 1)?

Answer 32

Cloudy corneas

Question 33

What do the eyes appear like in Hunter Syndrome (MPS type 2)?

Answer 33

No cloudy cornea Remember Hunters have sharp vision therefore no clouding of the cornea

Question 34

What is the pathophysiology of Gaucher disease?

Answer 34

Due a deficiency of glucocereborsidase enzyme which leads to deposition of glucocerebroside in cells of the macrophage-monocyte system This causes deposition in the spleen causing enlarged spleen and thrombocytopenia

Question 35

What are the features of Gaucher Disease?

Answer 35

Enlarged spleen - very significant Bone pain Hyperpigmentation Thrombocytopenia Anaemia

Question 36

What is the pathophysiology of Niemann-Pick disease?

Answer 36

Lipid storage disorder due to a deficiency of acid sphingomyelinase enzyme

Question 37

What are the features of type A Niemann Pick disease?

Answer 37

Common in Ashkenazi jews Hepatosplenomegaly Progressive loss of motor skills Cherry-red spot

Question 38

Which condition presents with episodic pain in the hands and feet, anihidrosus and corneal opacities?

Answer 38

Fabry Disease

Question 39

What is the pathophysiology of Fabry disease?

Answer 39

Deficient activity of lysosomal enzyme alpha galactosidase

Question 40

What diagnosis would seizures to auditory stimuli and cherry red spots point you in the direction of?

Answer 40

Tay-Sachs disease

Question 41

Which condition is associated with self mutilating behaviours (biting fingers and lips)?

Answer 41

Lesch-Nyhan disease

Question 42

How is the anion gap calculated?

Answer 42

(Na + K+) - (Cl + HCO3-) Normal anion gap is 8-12

Question 43

When a patient is lacking small intestine - how should they be fed?

Answer 43

Perenteral nutrition