Chapter 10, Problem 32P

A healthy couple with a history of three previous spontaneous abortions has just had a child with $\text{ cri-du-chat}$ the syndrome, a disorder caused by a terminal deletion of the chromosome $5$. Their physician orders karyotype analysis of both parents and of the child. The karyotype results for chromosomes $5$ and $12$ are shown here.

Are the chromosomes in the child consistent with those expected in a case of $\text{cri-du-chat}$ syndrome? Explain your reasoning.

Which parent has an abnormal karyotype? How can you tell? What is the nature of the abnormality?

Why does this parent have a normal phenotype?

Diagram the pairing of the abnormal chromosomes.

What segregation pattern occurred to produce the gamete involved in fertilization of the child with $\text{cri-du-chat}$ syndrome?

What is the approximate probability that the next child of this couple will have $\text{cri-du-chat}$ a syndrome?

Do the karyotypes of the parents help explain the occurrence of the three previous spontaneous abortions? Explain.