Unit 26

Question 1

What are some diseases related to single-gene defects?

Answer 1

• PKU (phenylketonuria)
• cystic fibrosis
• sickle cell anemia
• hemochromatosis (build up of blood iron levels)

Question 2

What are 4 things caused by polygenic defects?

Answer 2

1. heart disease
2. cancer
3. hypertension
4. obesity

Question 3

What are some causes of heart disease?

Answer 3

• high cholesterol diets –> plaque in some people
• diets low in folate and vegetables increases risk

Answer 4

T/F: most types of cancer are caused by the environment

Question 5

What causes hypertension?

Answer 5

salt sensitivty or salt resistant – eating too much salt usually increases BP but not in everyone

Question 6

How many genes are associated with development?

Answer 6

> 250

Question 7

What is celiac disease?

Answer 7

autoimmune disease that damages the small intestine

people with celiac have an immune reaction to gluten

Question 8

where is gluten found?

Answer 8

wheat, barley, rye

Question 9

What part of the immune system is attacked and destroyed?

Answer 9

the villi

Question 10

What is the genetic link with celiac disease?

Answer 10

celiac disease occurs in genetically predisposed people
- HLA genes (human leukocyte antigen), responsible for how the immune system distinguishes between body’s protein and foreign proteins

Question 11

What is seen in 99% of people with celiac disease and 60% with non-celiac gluten sensitivty?

Answer 11

DQ2 or DQ8 risk version of HLA (but 30% of the general population also have this variation)

Question 12

What are symptoms of celiac disease?

Answer 12

• headache
• fatigue
• abdominal pain and bloating after consuming product with gluten
• weight loss
• diarrhea
• constipation
• foul-smelling stools

Question 13

What percent of the canadian population is affected by celiac disease?

Answer 13

1%

Question 14

What is the chance of a family getting celiac if a 1st degree relative has celiac?

Answer 14

1 in 10 chance

Question 15

What does testing involve for celiac?

Answer 15

• blood test: tTG-IgA (tissue transglutaminase antibodies) – must be on glutain containing diet
• small intestine biopsy
• genetic screening

Question 16

What is celiac commonly misdiagnosed as?

Answer 16

• IBS
• Crohn’s disease

Question 17

What occurs with gluten sensitivity?

Answer 17

People develop symptoms when they consume gluten-containing foods but feel better on a gluten-free diet but do NOT have a celiac disease

Question 18

Are they antibodies for diagnosis of gluten sensitivity?

Answer 18

no, antibodies (TTG, EMA, DGP) are absent

Question 19

Does gluten sensitivity cause villous atrophy?

Answer 19

no

Question 20

What might be the cause of gluten sensitivity?

Answer 20

Other compounds in wheat, barley and rye (rpoteins called amylase/trypsin inhibitors or fermentable carbohydrates)

Question 21

What is nutrigenetics?

Answer 21

study of how genes and diet interact to increase or decrease someones risk for disease

gene x environment interactions

plays a role in personalized nutrition

Question 22

What sample do you need for nutrigenetics?

Answer 22

Saliva

Question 23

Is food selection influenced by genetics?

Answer 23

food preferences are largely learned but there are 80 genes that help taste bitter foods

Question 24

What is the furture of nutrigenetics?

Answer 24

individualized dietary prescriptions (complete profile with genetic risks, gut microbiota profiles etc)