Question

Just need to check if I am doing this correctly, I want to make sure my answers are correct for the parts I have answered... also I am confused how to answer question C. Thanks!!!!

2. Tom and Lindsey have just given birth to their fourth child, a girl named Katie. Soon after Katie's birth, Tom and Lindsey leamed that a routine newborn screening test showed that Katie has phenylketonuria (PKU), a genetic disorder in which phenylalanine cannot be digested by the body and can build up to toxic levels, causing mental retardation. Tom and Lindsey are familiar with PKU- their son Jake also has the disorder. When their son was first diagnosed with PKU, om and Lindsey visited a genetic counselor who gathered information about Tom and Lindsey's families. They also received information on how to treat Jake's PKU. They were relieved to learn that PKU can be treated with a restricted diet, one that is low in phenylalanine. Below is a pedigree of Tom and Lindsey's family. Examine the pedigree and answer the questions that follow. v A) Label the following persons on the pedigree: Tom, Lindsey, Jake, Katie. v B Label the proband on the pedigree using the standard symbol. C) What is the likely mode ofinheritance for this disorder? What evidence is there to support your answer? D Label the known carriers on the pedigree, using the standard symbol. v E) From whom did Lindsey inherit the PKU allele? Is there more than one possibility? Explain. Lindsey could have inherited the PKU from her mother OR her father. Because PKU is recessive then both of her parents most have had at least one recessive allele in order to give her heterozygous alleles. Either one parent was heterozygous and the other was homozygous recessive OR both parents were heterozygous V F) If Tom and Lindsey have a fifth child, what is the probability that the child will have PKU? 25% chance

Answer 1

PKU is human hereditary disease where the body fails to process phenylalanine found in protein we intake in our daily food. It is caused by recessive allele of simple Mendelian inheritance. It os causes when father and mother are heterozygotes.