Chapter 7, Problem 38P

Go to the OMIM website (https://www.ncbi.nlm.nih.gov/omim) and type “dyskeratosis congenital autosomal dominant 1” (DKCA1) into the search bar. The result will include a clickable link to the disorder that has an OMIM number of $127550$. Review the OMIM information you retrieve and notice that this disorder is caused by a mutation of a telomerase gene that results in abnormally rapid shortening of telomerase and the appearance of disease symptoms at progressively younger ages in successive generations of the affected families. Use this and other information on OMIM to assist with this problem.

Go the reference number $15$ at the bottom of the OMIM page for a link to a $2004$ paper by Tom Vulliamy and colleagues that appeared in the journal Nature Genetics. Click on the “Full text” option and download a copy of the paper. Look at Table 1 of the paper on page $448$. This table lists the lengths of telomeres measured in members of families in this study. Telomeres shorten with age, and telomere lengths in Table 1 are age-adjusted. The negative numbers for telomere lengths in the table indicate that telomeres are shorter than average for age, and the more negative the number, the shorter the telomere. Based on Table $1$, discussion in the Vulliamy et al. ( $2004$)paper, and information available on OMIM answer the following:

a. How do telomere lengths in children compare with telomere lengths of their parents?

b. Why are telomeres of people with DKCA $1$ shorter than average?