Metabolic Medicine

Question 1

Mutation of HPRT1 gene

Answer 1

Lesch-Nyhan syndrome

Question 2

What is Lesch-Nyhan syndrome

Answer 2

Characterised by the overproduction and accumulation of uric acid

Question 3

Characterised by self-injury (i.e. head banging and self biting)?

Answer 3

Lesch-Nyhan syndrome

Question 4

Inheritance of Lesch-Nyhan syndrome?

Answer 4

X-linked recessive

Question 5

Associated with oil drop cataracts

Answer 5

Galactosaemia

Question 6

Due to a mutation in the galactose-1-phosphate uridyltransferase gene on chromosome 9

Answer 6

Galactosaemia

Question 7

Associated with e-coli sepsis

Answer 7

Galactosaemia

Question 8

What is Hartnup disease?

Answer 8

Metabolic condition affecting the transport of amino acids in the kidneys and small intestine

Question 9

First presentation is with photosensitivity and symptoms of pellagra (diarrhoea and dermatitis)?

Answer 9

Hartnup disease

Question 10

What is Alkaptonuria?

Answer 10

Characterised by homogentistic acid oxidase deficiency - leads to an accumulation of homogentistic acid (passed in the urine however if urine left standing it rapidly oxidises forming a black pigment)

Question 11

Symptoms of Alkaptonuria?

Answer 11

Homogentistic deposition in the cartilage leading to grey discolouration in young adulthood
Deposition in cardiac tissue - aortic stenosis

Question 12

Characterised by a deficiency of aldolase B?

Answer 12

Hereditary fructose deficiency

Question 13

Name the types of organic acidaemia?

Answer 13

Maple syrup urine disease
Propionic academia
Methylmalonic acidaemia
Isovaleric acidaemia

Question 14

Investigation of choice for organic acidaemia?

Answer 14

Raised blood and urine amino acids (leucine, isoleucine and valine)

Question 15

Exacerbated by infection and periods of high protein intake?

Answer 15

Organic acidaemia

Question 16

Treatment is with a low protein diet?

Answer 16

Organic acidaemia

Question 17

What are the causes of a increased anion gap acidosis?

Answer 17

Methanol
Uraemia
DKA/ AKA
Paraldehyde/ phenformin
Iron
Lactic acidosis
Ethylene glycol
Salicylates

Mneumonic MUDPILES

Question 18

What causes a normal anion gap acidosis? i.e hyperchloraemic metabolic acidosis

Answer 18

Gastrointestinal bicarbonate loss: diarrhoea, ureterosigmoidostomy, fistula
Renal tubular acidosis
Drugs: e.g. acetazolamide
Ammonium chloride injection
Addison’s disease

Question 19

What is the treatment of choice for acute attacks in MCADD?

Answer 19

10% dextrose

Question 20

Usually presents as an inability to generate energy during periods of high demand?

Answer 20

MCADD

Question 21

May present with hypoglycaemia, hepatic encephalopathy or sudden infant death syndrome

Answer 21

MCADD

Question 22

Site of ribosome production

Answer 22

Nucleolus

Question 23

Site of translation and folding of new proteins?

Answer 23

Rough endoplasmic reticulum

Question 24

Site of steroid and lipid synthesis?

Answer 24

Smooth endoplasmic reticulum

Question 25

Modifies, sorts and packages molecules that are destined for cell secretion?

Answer 25

Golgi apparatus

Question 26

Site of DNA maintenance and RNA transcription?

Answer 26

Nucleus

Question 27

Site of breakdown of large molecules such as proteins and pilysaccharides?

Answer 27

Lysosomes

Question 28

Site of translation of RNA into proteins?

Answer 28

Ribosomes

Question 29

Involved in degradation of protein molecules that have been tagged with ubiquitin

Answer 29

Proteasome

Question 30

Investigations for peroxisomal disorders?

Answer 30

Elevated very long chain fatty acids Elevated bile acid intermediates Elevated phytanic acid and pipecolic acid

Question 31

Signs of rickets?

Answer 31

In toddlers - genu varum (bow legs), in older children - genu valgum (knock knees) 'Rickety rosary' - swelling at the costochondral junction Kyphoscoliosis Craniotabes - soft skull bones in early life Harrison's sulcus

Question 32

Normal blood gas in pregnancy?

Answer 32

Compensated respiratory alkalosis

Question 33

Causes of hypercalcaemia?

Answer 33

C alcium supplementation H yperparathyroidism I atrogentic (Drugs: Thiazides) M ilk Alkali syndrome P aget disease of the bone A cromegaly and Addison's Disease N eoplasia Z olinger-Ellison Syndrome (MEN Type I) E xcessive Vitamin D E xcessive Vitamin A S arcoidosis

Question 34

Cherry red spot with neurological deterioration and no evidence of hepatosplenomegaly?

Answer 34

Tay-Sachs disease

Question 35

Cherry red spot with neurological deterioration and hepatosplenomegaly?

Answer 35

Niemann Pick syndrome

Question 36

Which form of Niemann Pick does NOT present in children>

Answer 36

Type E

Question 37

Causes of a cherry red spot?

Answer 37

Central retinal artery occlusion Niemann-Pick Tay-Sachs Sandhoff disease Multiple Sulfatase Deficiency Mucolipidosis Type 1 and 2

Question 38

Phenylalanine hydroxylase deficiency

Answer 38

PKU

Question 39

Cystathionine beta synthase deficiency

Answer 39

Homocysteinuria

Question 40

Beta-N-acetylhexosaminidase A deficiency

Answer 40

Tay-Sachs disease

Question 41

Glucosylceramidase deficiency

Answer 41

Gaucher's disease

Question 42

Sphingomyelinase deficiency

Answer 42

Neimann-Pick disease

Question 43

Musty smell?

Answer 43

PKU

Question 44

What are the causes of a normal anion gap?

Answer 44

Hyperventilation Acetazolamide Renal tubular acidosis Diarrhoea Ureteral diversion Pancreatic fistula

Question 45

Which 6 metabolic conditions are tested for on Guthrie heel prick?

Answer 45

Phenylketonuria (PKU) Medium-chain acyl-CoA dehydrogenase deficiency (MCADD) Maple syrup urine disease (MSUD) Isovaleric acidaemia (IVA) Glutaric aciduria type 1 (GA1) Homocystinuria (pyridoxine unresponsive) (HCU)

Question 46

Where is calcitonin released from?

Answer 46

C cells of the thyroid