Telomere length is altered in individuals with <i>RTEL1^R1264H</i>.

<p>(A) Primary lymphocyte telomeres in family NCI-318 were measured by flow cytometry with fluorescent <i>in situ</i> hybridization (FISH) <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1003695#pgen.1003695-Alter2" target="_blank">[3]</a>. The proband is indicated by a triangle, the mother by a circle, and the father by a square. (B) Telomere FISH analysis of MSK-41 hTERT-immortalized fibroblasts revealed extreme telomere length heterogeneity. Quantitation of chromatids lacking detectable telomeric signal is shown. BJ hTERT, a normal hTERT-immortalized fibroblast line, and SaOS-2, an osteosarcoma cell line that relies on recombination-based telomere maintenance (ALT), are presented for comparison. (C) Representative metaphase spreads of MSK-41 and BJ hTERT are shown.