Developmental Disorders

Question 1

Define anomaly and malformation.

Answer 1

Anomaly - Any deviation from the expected or average form and/or function which is interpreted as abnormal.
Malformation - Morphological defect of an organ/region of the body resulting from an intrinsically abnormal developmental process

Question 2

What is the most common congenital cardiac defect and describe its features

Answer 2

• Ventricular septal defect.
• Often associated with syndromes (anomaly thought to be pathogenetically related) like Down’s.
• Usually symptomless at birth and manifests a few weeks later.
• Acyanotic congenital heart defect due to left to right shunt so there are no signs of cyanosis at an early stage. However uncorrected VSD can increase pulmonary resistance and cause shunt reversal leading to cyanosis.

Question 3

Describe features of spina bifida

Answer 3

• Myelomeningocele
• Neural tube defect where the caudal end of the neural tube fails to close.
• Causes neural tissue to protrude from the sacral region

Question 4

What are the common clinical features of down’s syndrome?

Answer 4

• Mental retardation,
• flat facial profile
• Low set ears,
• Protruding tongue,
• Congenital heart defects.
• Abundant neck skin
• single palmer crease
• Intestinal stenosis
• Umbilical hernia
• Hypotonia
  = Predisposition to leukaemia

Question 4

What is ectopia cordis?

Answer 4

Displacement of the heart outside the body

Question 5

What is a harmartoma?

Answer 5

Tumour-like malformation composed of mature normal cells in a usual location but as a disorganised mass.

Question 6

Describe features of Peutz-Jeghers syndrome

Answer 6

• Mucocutaneous pigmentation
• Hamartomatous polyposis in jejunum and ileum

Question 7

Define diverticulum

Answer 7

• Circumscribed pouch/sac caused by herniation of lining of mucosa of an organ through defect in muscular coat.
• Examples include meckel’s diverticulum and diverticular disease

Question 8

Describe features of Meckel’s Diverticulum

Answer 8

• Congenital diverticulum which is two inches long, usually at the terminal ileum.
• It is a remanence of the yolk sac which failed to involute.
• It contains all the layers of the intestinal wall with ectopic tissue within it.

Question 9

What are the complications of a Meckel’s diverticulum

Answer 9

• Inflammation (may mimic appendicitis),
• Bleeding from ulcerated gastric tissue,
• Perforation,
• Obstruction/intussusception

Question 10

Describe features of diverticular disease

Answer 10

Most common in sigmoid colon. Occurs due to poor dietary fibre which results in muscular hypertrophy, which increases intraluminal pressure and causes outpouching of the mucosa.
These outpouchings can fill with faeces and become inflamed and may even rupture.

Question 11

What is intussusception?

Answer 11

Invagination of a portion of the intestine. It is common between ages 5-9 months. 90% at ileocaecal valve. Progressive compression of blood supply causes haemorrhagic necrosis