Inheritance of dominant traithuntington's disease (hd) is an incurable, fatal neurological disease caused by a dominant allele on chromosome 4. the median age of onset of hd symptoms is about 38 years. jonathan is a 33-year-old individual whose mother had hd. neither his father nor his much older brother who is 45 years old show any signs of hd. which statements is/are accurate with regards to jonathan and his family? check all that apply. a. jonathan's mother has the genotype hhb. jonathan's father has the genotype hhc. jonathan's older brother likely has the genotype hhd. the chance of jonathan having an hh genotype is 1/4e. the chance of jonathan having hd is 1/2f. the chance of jonathan being heterozygous for the hd allele is 1/2