Biochem

Question 1

Enzymes containing selenocysteine

Answer 1

Thioredoxin reductase
Glycine reductase
Glutathione peroxidase
Deiodinase
Selenoprotein p

Question 2

Most common mutation of cystic fibrosis(AR)

Answer 2

Phenylalanine at 508

Question 3

Dye used in real time PCR for SARS-COV-2

Answer 3

SYBR green dye

Question 4

HCC
Rancid butter odour
Boiled cabbage smell in urine

Answer 4

Tyrosinemia I
Fumarylacetoacetate hydrolase deficiency

Question 5

Swimming pool odour

Answer 5

Tyrosinemia III
Para hydroxy phenyl pyruvic acid hydrolase deficiency
Hawkinuria
Neonatal tyrosinemia

Question 6

Guthric test

Answer 6

Bacillus subtilis grows on phenylalanine

Question 7

Fasting hyperglycemia
Lactic acidosis
Hyperuricemia
Hyperlipidemia
Ketosis

Answer 7

Von gierkes disease
Glucose 6 phospatase deficiency

Question 8

Muscle weakness
Heart failure
Death by 2 years

Answer 8

Pompe’s disease
Lysosomal acid maltase / α1,4→α1,6 glucan transferase deficiency

Question 9

Fasting hypoglycemia
Biopsy - Glycogen with short branches

Answer 9

Cori’s disease/ Limit Dextrinosis
Debranching enzyme deficiency

Question 10

Severe fasting hypoglycemia
Biopsy - linear glycogen
Death by 5 years

Answer 10

Anderson’s disease / Amylopectinosis
Branching enzyme deficiency

Question 11

Extreme muscle weakness
Exercise intolerance

Answer 11

McArdle’s disease
Muscle glycogen phosphorylase deficiency

Question 12

Mild fasting hypoglycemia
Well tolerated

Answer 12

Her’s disease
Hepatic Glycogen phosphorylase deficiency

Question 13

Muscle weakness
Hemolysis

Answer 13

Tauri’s disease
Muscle and RBC: PFK 1 deficiency

Question 14

6m/o - on weaning
Vomiting
Diarrhoea
Acute liver failure

Answer 14

Hereditary fructose intolerance
Aldolase B deficiency

Question 15

Neonate(<1month)
Vomiting
Diarrhoea
Acute liver failure
B/L congenital cataract

Answer 15

Classical galactosemia
Gal 1 P Uridyltransferase deficiency

Question 16

Muscle weakness
Excercise intolerance
Cola coloured urine

Answer 16

Carnitine deficiency - t/t carnitine
CPT 1 deficiency - not treatable
❌ β oxidation in muscles
Cola coloured urine - myoglobinuria

Question 17

Foreign fruit ingestion
Fasting hypoglycemia
Vomiting
Convulsions

Answer 17

Jamaican vomiting sickness
Ackee fruit - hypoglycin → (-)Med Chain Acyl CoA dehydrogenase deficiency
❌ β oxidation in liver

Question 18

Foam like histiocyte
Cherry red spot
Organimegaly

Answer 18

Neimann pick disease (AR)
Sphingomyelinase deficiency
Urine sphingomyelin

Question 19

Angiokeratoma
Hypohidrosis
Corneal clouding

Answer 19

FABRY disease (X linked)
α Galactosidase deficiency
Urine - Trihexose ceramide

Question 20

Mental retardation
Myotonia
Wide epicanthal folds
Low set ears

Answer 20

Hurlers disease - Mucopolysaccharidoses I- α-L-Iduronidase deficiency - corneal clouding(+)

Hunters disease - Mucopolysaccharidoses II- Iduronate sulphate deficiency - corneal clouding(-)

Question 21

Cerebellar ataxia
Retinitis pigmentosa
Peripheral neuropathy
↑CSF pressure

Answer 21

Refsum disease - mild peroxisomal biogenesis disorder - phytanolyl CoA α hydroxylase deficiency

T/t No dairy, green leafy vegetables

Other PBDs
Moderate - Adrenal leucodystrophy
Severe - Zellweger syndrome - peroxisomal agenesis - Accumulation of VLCFA - cerebrohepatorenal syndrome

Question 22

ω oxidation defect

Answer 22

Dicarboxylic aciduria