Chemical Pathology 5 - Metabolic disorders and screening Flashcards

1
Q

Deficiency of which enzyme causes phenylketouria?

A

Phenylalanine hydroxylase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What builds up in PKU that causes toxicity?

A

Tyrosine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What number must you use when requesting a metabolic screen?

A

OMIM number

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What will be the result of not treating PKU shortly after birth?

A

IQ <50

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How is PKU diagnosed?

A

Based on blood phenylalanine level, as >400 different mutations can cause PKU!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How quickly does PKU treatment need to be initiated in order to be effective?

A

First 6 weeks of life

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the test for cystic fibrosis in the neonate?

A

High immune reactive trypsin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is MCADD?

A

Enzyme deficiency that prevents production of acetyl CoA, which permits glucose sparing
Therefore, if you can’t break down fat, you may die of hypoglycaemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What metabolic defect can cause hyperammonaemia?

A

Urea cycle defect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How can hyperammonaemia be treated?

A

Remove ammonia via sodium benzoate or sodium phenyl acetate

Reduce ammonia production (low protein diet)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the typical triad of signs for organic aciduria?

A

Hyperammonaemia
Metabolic acidosis
High anion gap

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What unusual odour might be smelt on a patient with isovaleric acidaemia?

A

Cheesy and sweaty

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the typical neurological findings in organic acidurias?

A

Truncal hypotonia and limb hypertonia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What condition causes chronic intermittent organic aciduria?

A

Reye syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Recall 3 drugs that can precipitate symptoms in Reye syndrome

A

Salicylates
Anti-emetics
Valporate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What specialist test should be done in cases of hyperammonaemia?

A

Blood spot carnitine profile

17
Q

Which inherited metabolic disorder causes a hypoketotic hypoglycaemia?

A

MCADD

18
Q

What is the most common disorder of carbohydrate metabolism?

A

Gal-1-put

19
Q

How should Gal-1-Put be treated?

A

Abstain from drinking milk

20
Q

What may be the consequence of not identifying MCADD in infancy?

A

Bilateral cataracts

21
Q

Recall 3 signs of glycogen storage disease type 1

A

Hypoglycaemia
Neutropaenia
Lactic acidosis

22
Q

How does Gal-1-Put present in neonates?

A

Diarrhoea
Vomiting
Conjugated bilirubinaemia

23
Q

When, and in which organ, do mitochondrial disorders present?

A

At any age in any organ!

24
Q

Recall 3 mitochondrial disorders

A

BARTH syndrome
MELAS
Kearns Sayre syndrome

25
Q

What abnormal blood results would be suggestive of a mitochondrial disorder?

A

Elevated lactate, even when fasted

Unexplained raised CK

26
Q

What is the typical histological finding in mitochondrial disorders?

A

Ragged red fibres