Modes of Mendelian Inheritance
Associated with AI |
| Autosomal Dominant Inheritance |
- Can have male to male transmission.
- On average, half of the offspring of an affected individual
will be affected. There is a 50% chance for the child of
an affected individual to be affected.
- Affected males and females have similar clinical presentation.
|
| Autosomal Recessive Inheritance |
- Unaffected parents will have affected offspring.
- On average, one in four offspring of carrier parents will
be affected.
- More likely to occur when parents are related (consanguineous
relationship).
|
| X-linked recessive inheritance |
- Do not have male to male transmission.
- All daughters of an affected male are carriers.
- Half of the sons born to a carrier female will be affected.
- Affected males have more severe manifestations than females.
- Females can show no manifestations to severe manifestations
due to lyonization. Females express only one X chromosome
per cell with the other X chromosome becoming the bar body.
If adequate numbers of cells express the X chromosome carrying
the mutant allele, they will have varying degrees of the
enamel defect.
|
To understand the molecular basis of the different AI conditions
a basic understanding of human genetics is helpful. There are numerous
WEB sites offering very basic to highly advanced information on
human genetics. Links to several of these WEB sites are provided
below.
