The following pedigree chart shows the inheritance of a genetic disorder. I-2 and III-2 are the only affected individuals.
Which one of the following is the correct pattern of inheritance of the disorder, and the genotype of the II-3 individual?
1
Autosomal recessive, homozygous for the normal allele
2
Autosomal dominant, homozygous for the normal allele
3
X-linked recessive, heterozygous
4
Autosomal recessive, heterozygous