Pedigree Flashcards
What are the symbols for male and female on a pedigree?
Male is a square
Female is a circle
What are the symbols for affected, unaffected and carrier on a pedigree?
Unaffected is white
Affected is black
Carrier is half white half black
X linked recessive female carrier is a black dot in the centre of the circle
How is a pregnancy shown on a pedigree?
By a diamond coming from the centre of the marriage line between the parents
How are the consultand and proband shown on a pedigree?
Consultand is shown by a C
Proband is shown by an arrow pointing to them
How is a miscarriage shown on a pedigree?
By a small black dot coming from the centre of the marriage line between the parents
How is a consanguineous marriage shown on a pedigree?
By double lines drawn between the couple
Who are the consultand and proband?
The consultand is the person seeking advice
The proband is the person who prompted the consultand to seek advice i.e. the person woth the condition
In what order should siblings be shown on a pedigree?
In order of age
Oldest to youngest, left to right
A pedigree which shows a vertical pattern of inheritance where both males and females and there is male to male transmission are affected indicates what kind of mode of transmission?
Autosomal dominant
A pedigree which shows a horizontal pattern of inheritance where both males and females are affected and there is male to male trnasmission indicates what kind of mode of transmission?
Autosomal recessive
What is meant by ‘knights move inheritance’ on a pedigree and what mode of inheritance does this demonstrate?
This is where two affected males are related through an unaffected female
X linked recessive
If a consultand was found to haven the breast cancer gene then what advice would be given?
Advice in diet and exercise
Not smoking / smoking cessation
Not take to contraceptive pill or hormone replacement therapy
Prophylactic surgery offered
What mode of inheritance is shown in albinism?
Autosomal recessive
What mode of inheritance is shown in cystic fibrosis?
Autosomal recessive
What mode of inheritance is shown in duchenne muscular dystrophy?
X linked recessive
