7.5 Genetics and Digestive Disorders

Question 1

What is the genetic inheritance pattern of hereditary haemochromatosis

Answer 1

Autosomal recessive.

Question 2

IBD can be caused by genetic factors relating to genes that control…

Answer 2

• Epithelial barrier
• Neutrophil/T/B cell activity
• Autoinflammation

Question 3

Give two examples of genetics conditions that predispose to IBD

Answer 3

• Turner syndrome (missing X chromosome in women)
• Glycogen storage disease Type 1

Question 4

Which genes is coeliac disease associated with (in terms of function, not name)

Answer 4

• Genes that influence MHC class II
• These are in a region known as HLA D, found on the short arm of Chromosome 6

Question 5

Which gene is affected in hereditary haemochromatosis? What is the effect of this?

Answer 5

• HFE protein is affected
• Causes decreased production of hepcidin

Question 6

Amyloidosis: pathogenesis, signs, and symptoms (all systems)

Answer 6

• Pathogenesis: deposition of extracellular, insoluble amyloid protein (can be chornic disease related or heritable)
• Signs/symptoms include restrictive cardiomyopathy, narpal tunnel syndrome, portal hypertension, lung nodules

Question 7

Cystic fibrosis: pathogenesis, signs, and symptoms

Answer 7

• Pathogenesis: CFTR chloride transporter dysfunction, causing thickened mucous 2° to decreased secretions
• Signs/symptoms: productive cough, dyspnoea, recurrent lung infections

Question 8

Amyloidosis GI symptoms, and mechanisms

Answer 8

• Mucosal amyloid infiltration and erosion -> malabsorption
• Deposition in neuromuscular layer -> motility issues
• Deposition in tongue -> macroglossia

Question 9

Cystic Fibrosis GI symptoms, and mechanisms

Answer 9

• Pancreatic congestion -> fat malabsorption, pancreatitis, decreased insulin production (?diabetes-like)
• Cholelithiasis
• Liver congestion -> hepatic fibrosis