2009 Remembered

Question 1

1. A 15 year old girl with delayed puberty is seen in the clinic. A karyotype shows mosaic Turner syndrome [45,X (22); 46,XX (8)].

Which of the following investigations is essential prior to commencing pubertal induction?

A. Bone age assessment.
B. Follicle-stimulating hormone (FSH) level.
C. Insulin-like growth factor I (IGF-I) level.
D. Oestradiol level.
E. Pelvic ultrasound.

Answer 1

B. Follicle-stimulating hormone level

Elevated FSH will confirm gonadal failure. If FSH normal, a pelvic ultrasound to determine if follicles are present as a predictor of gonadal status. (apeg.org.au)

Question 2

A 3 week old baby of Somali parents presents with convulsions. Investigations include:

Serum calcium 1.60 mmol/L [2.15-2.60]
Phosphate 2.1 mmol/L [1.1-1.8]
25-hydroxyvitamin D (25 OHD) 40 nmol/L [30-150]
Parathyroid hormone (PTH) 1.0 pmol/L [1.2-6.4]
Magnesium 0.5 mmol/L [0.7-1.1]
Alkaline phosphatase (ALP) 300 U/L [100-350]

Which of the following is the most likely diagnosis?

A. Congenital hypomagnesaemia.
B. Congenital hypoparathyroidism.
C. Hypophosphataemia.
D. Pseudohypoparathyroidism.
E. Vitamin D deficiency.

Question 3

8. Pancreatic enzymes are involved in digestion of protein. They are released as proenzymes into
   the duodenal lumen where they are activated.
   The enzyme that plays an important role in activating the proenzymes is:

A. carboxypeptidase.
B. chymotrypsin.
C. elastase.
D. lipase.
E. trypsin.

Answer 3

Answer E. Trypsin

Chymotrypsin is converted to trypsin by small intestine enzyme enterokinase. Activated trypsin further activates chymotrypsin and other proteases.

Question 4

12. A 2 year old boy is brought to the Emergency Department with a history of several days of rectal
    bleeding. His mother first noticed reddish-coloured stools three days prior and since then has
    changed a few nappies containing only blood. On examination the child is afebrile, alert and
    playful and is eating well. He is tachycardic and abdominal examination is normal.
    Which of the following investigations will most likely reveal the diagnosis?

A. Abdominal ultrasound.
B. Barium enema.
C. Gastroscopy.
D. Radionuclide scan.
E. Stool culture.

Answer 4

Answer D. Radionuclide scan.

Diagnosis in Meckel Diverticulum.

60% of complications arise in