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Flashcards in Genetics Deck (42)
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1

What is meant by a monogenic gene disorder?

Due to a single gene mutation

2

What are the 6 patterns of inheritance by which a monogenic gene disorder can be passed on?

Autosomal Dominant
Autosomal Recessive
X linked dominant
X linked recessive
Y-linked
Mitochondrial

3

What is meant by a polygenic gene disorder?

- Multiple genes involved
- Often environmental influences
- Evaluated by looking at large populations

4

Describe what is meant by high penetrance?

If the patient has the gene mutation they are extremely likely to have the disease

5

If both parents are carriers for a recessive mutation, what is the likelihood of the child inheriting the disease?

1 in 4

6

Autosomal dominant usually skips generations. TRUE/FALSE?

FALSE
usually appears in every generation

7

If males can only pass a genetic disorder to females, but females can pass it to either sex, what pattern of inheritance is this?

X-linked dominant

8

If males are always affected, yet females can become carriers, what pattern of inheritance does this describe?

X-Linked Recessive

9

If only males are affected by a genetic disease, what does this indicate about its inheritance pattern?

It is Y-linked as only males have a Y-chromosome

10

Describe what is meant by a mitochondrial inheritance pattern

Inherited through mother's mitochondrial DNA whilst in the womb
=> can only inherit it from mother

11

Explain what benign tumours usually present in Multiple Endocrine Neoplasia Type 1 (MEN1)

Benign:
- Non-secreting Islet cell tumour
- Non-secreting pituitary tumour
- adrenal cortex

12

What malignant tumour usually presents in MEN1?

Foregut carcinoid tumour
(secretes gastrin, glucagon and polypeptides)

13

What benign or malignant tumours are found in Multiple Endocrine Neoplasia Type 2?

C-cell
Adrenal Chromaffin

14

What gene defect is found in Multiple Endocrine Neoplasia Type 2?

RET

15

What hormones are secreted in Von Hippel Lindau syndrome?

Catecholamines

16

What type of gene is the MEN1 gene

A tumour suppressor

17

What section of the MEN1 gene is usually mutated in Multiple endocrine Neoplasia Type 1?

11q

18

Both MEN1 and MEN2 are autosomal dominant. TRUE/FALSE?

TRUE

19

What section of the RET gene is usually mutated in MEN2 and what type of gene is it?

10q
RET = proto-oncogene

20

MEN mutations in MEN1 usually occur in very specific areas of the codon. TRUE/FALSE?

FALSE
RET mutations in MEN2 act in very specific cysteine residues, whereas in MEN1 they can occur anywhere along the length of the codon.

21

What three areas are usually affected by tumours in MEN1?

Pituitary
Pancreas
Parathyroid

22

What tumour found during MEN1 is the most fatal?

Pancreatic neuroendocrine tumour

23

After what size should an MEN1 pancreatic tumour be referred for surgical intervention?

>2cm

24

What tumours usually present in MEN2a?

Parathyroid hyperplasia
Medullary Thyroid Carcinoma
Phaechromocytoma

25

What tumours are usually present in MEN2b?

Mucosal Neuromas
Medullary Thyroid Carcinoma
Phaechromocytoma
**Marfan's Syndrome is also present**

26

What prophylactic treatment can be used in MEN2 for Medullary Thyroid Cancer?

Prophylactic Thyroidectomy

27

At what age is it important to screen for Phaechromocytoma and Parathyroid disease?

Between ages 11 and 16
>11 = High Risk
>16 = moderate Risk

28

How do patients with Carney Complex usually present?

Spotty pigmentation of the skin:
- lips
- eyes
- genitals

29

Where do myxomas usually present in Carney Complex patients?

Breast
Cardiac

*generally myxomas can be cutaneous or mucosal*

30

What cancers often present in the Carney Complex

Thyroid carcinoma
GH producing pituitary Adenoma (causing Acromegaly)