Lecture 10

Question 1

What does family history provide?

Answer 1

Provides valuable information about an individuals’ risk for specific health conditions.

Question 2

The mnemoic for red flags for genetic disease are: FGENES. what does it stand for?

Answer 2

F- Family history
G- Group of congenital anomalies
E- Extreme/exceptional presentation of common conditions
N- Neurodevelopmental delay or degeneration
E- extreme or exceptional pathology
S- Surprising laboratory value

Question 3

What is a pedigree?

Answer 3

a pictorial representation of a family medical history, using standard symbols

Question 4

What does a diamond mean on a pedigree?

Answer 4

sex not specified

Question 5

What is a proband?

Answer 5

First individual in a family who potential genetic disorder to the attention of a healthcare professional

Indicated by an arrow

Question 6

What does a double line mean in a pedigree symbol?

Answer 6

indicates partners are related biologically
ex: first or second cousins

Question 7

How do you represent dizygotic vs monozygotic twins on a pedigree?

Answer 7

For dizygotic twins, they have a diagonal line

For monozygotic twins, they will have a diagonal line with a line connected the two

Question 8

What do you do for a pregnancy loss on a pedigree?

Answer 8

A small symbol is shown
if they didn’t know the gender, a diamond is shown

Question 9

What do you do for an adoption into and out of the family?

Answer 9

Adopted into the family: There is a bracket around the symbol and a dotted line connecting them to the family

Adopted out of the family: A straight line connected to the family. A bracket is facing outward.

Question 10

How many generations does a pedigree have to how?

Answer 10

3 generations

Question 11

What can a pedigree analysis suggest?

Answer 11

an inheritance model for a genetic disorder.

Question 12

What are the main monogenic inheritance models? 6 models

Answer 12

Autosomal dominant
Autosomal recessive
X-linked dominant
X- linked recessive
Y-Linked
Maternal (Mitochondrial)

Question 13

What happens if it is more then one models fits?

Answer 13

choose the more likely model

Question 14

What are the rules of Y-linked inheritance?

Answer 14

Only males inherit Y-linked traits
Are there any affected females?
All sons of an affect male are affected
Are there any unaffected sons of affected males?

Question 15

Maternal (mitochondrial) inheritance rules?

Answer 15

Mitochondrial traits are inherited from an affected mother
Are there affected individuals with affected father, but unaffected mother?

Question 16

X-linked dominant rules?

Answer 16

All daughters of an affected male
Are there affected individuals with affected father, but unaffected mother

Question 17

X-linked recessive rule

Answer 17

All sons of an affected female are affected
Are there unaffected sons of affected females?

Question 18

Autosomal dominant rules?

Answer 18

No carriers
Affected individuals have at least one parent affected
Are there any affected individuals with both parents unaffected?

Question 19

Autosomal recessive rules?

Answer 19

often skips generations

Question 20

Out of all 6 models which are more common and which are less common?

Answer 20

More common:
Autosomal dominant
Autosomal recessive
X-linked recessive

Less common:
X-linked dominant
Y-linked
Maternal (mitochondrial)

Question 21

What are complications of monogenic disorders?
not really important

Answer 21

Incomplete penetrance
Phenotypic variability
Polygenic disorders
epigenetic factors
Multifactorial disorders