a. The abnormalities are supposed to be the result of the same gene since it is highly impossible for two genes to be responsible for two different abnormalities to be in a person at the same time.
b. Both sons and daughters seem to inherit from affected fathers hence, the allele appears to be autosomal.
c. The pedigree shows that the trait appears to be dominant but with incomplete penetrance. The non-related individuals marrying into the pedigree have to be heterozygous in order to make the trait to be recessive – I-1, I-3, II-8, II-11 etc. The individuals II-4, II-14, III-2 and III-14 paved way for the passage of the disorder to the descendants although they do not themselves express them. Hence, 4 out of every 20 people could be inferred of possessing the gene showing that there is an 80 percent penetrance.
It should also be noted that out of the 16 individuals showing blue sclera 10 of them do not show brittle bones. This proves that the pedigree exhibits variable expressivity as well.