Final answer:
Neurofibromatosis type 1 is the autosomal dominant disorder with incomplete penetrance from the options provided. It can lead to tumor formation and individuals with the gene may or may not show symptoms. Option 4 is correct.
Step-by-step explanation:
The autosomal dominant disorder with incomplete penetrance among the options given is Neurofibromatosis type 1. Incomplete penetrance refers to the phenomenon where not all individuals with a faulty gene show signs or symptoms of the disease.
Neurofibromatosis type 1 is characterized by tumor formation within the nervous system, leading to skin and skeletal deformities. A person with this disorder may have a 50 percent chance of passing the dominant allele to their offspring, as demonstrated by a Punnett square.
Huntington's disease is another example of an autosomal dominant disorder, but it does not show incomplete penetrance; typically, if an individual has the allele for Huntington's, they will eventually express the disease. Marfan syndrome and achondroplastic dwarfism also follow an autosomal dominant inheritance pattern.
Therefore, option 4 is correct.