Evolutionary Continuity of Autosomal Dominant Inheritance between Haplogroups:

If a male in one haplogroup has an autosomal dominant disorder, there is a 50% chance of passing that 
autosomal dominant disorder on to his offspring.

Example:

http://ghr.nlm.nih.gov/handbook/illustrations/patterns?show=autodominant

“In this example, a man with an autosomal dominant disorder has two affected children and two unaffected 
children.”

As this lineage evolves, the unaffected and affected children will mutate into other downstream haplogroups. 
The ancestral lineage of the male afflicted with the autosomal dominant disorder may die off, but its younger 
progeny continues to have a 50% chance of passing the autosomal dominant disorder on to their offspring 
in a continuing downward or younger haplogroup spiral.

If the ancestral lineage of the male afflicted with the autosomal dominant disorder continues to survive then 
those males who inherited the autosomal dominant disorder should exhibit some form of relatedness to the 
older haplogroup lineage of the autosomal dominant disorder.    

http://ghr.nlm.nih.gov/handbook/inheritance?show=all

Inheriting Genetic Conditions

Inheritance patterns and understanding risk

http://ghr.nlm.nih.gov/handbook/inheritance?show=all#riskassessment

"If a genetic disorder runs in my family, what are the chances that my children will have the condition?

When a genetic disorder is diagnosed in a family, family members often want to know the likelihood that they or 
their children will develop the condition. This can be difficult to predict in some cases because many factors 
influence a person’s chances of developing a genetic condition. One important factor is how the condition is 
inherited. For example:
 
Autosomal dominant inheritance: A person affected by an autosomal dominant disorder has a 50 percent chance 
of passing the mutated gene to each child. The chance that a child will not inherit the mutated gene is also 50 
percent (illustration)."

http://ghr.nlm.nih.gov/handbook/illustrations/patterns?show=autodominant

Further information available at:

http://www.genetics.com.au/pdf/factsheets/fs09.pdf

Autosomal Dominant Inheritance

"When one parent is a carrier of an autosomal dominant faulty gene, there is 1 chance in 2, or 50% chance, in 
every pregnancy that their child will be affected by, or predisposed to developing the condition. So there is an 
equal chance that they will neither be affected nor predisposed to developing the condition

Where both parents are carriers of an autosomal dominant faulty gene, there is 1 chance in 4, in every pregnancy, 
that their child will receive the faulty gene copy from both parents and be more severely affected by the condition

Where neither parent is a carrier of a dominant faulty gene and they have a child affected by a condition known to 
be due to autosomal dominant inheritance, the condition will most likely be due to a new or spontaneous change 
in that gene. Rarely, the parent will have the mutation in some of their egg or sperm cells."