Figure 4.

Longitudinal Analysis of ULSAM-340, a Single-Born Subject Containing a 13.8 Mb Deletion on 20q, as Detected by LRR and BAF with the Illumina SNP Array

The size and position of this deletion is typical of MDS patients. This subject, however, has not been diagnosed with MDS. When the patient was 71 years old, the deletion was only carried by a small proportion of blood cells and was barely detectable, and neither Nexus Copy Number software nor R-package MAD reported this aberration at this age (A, D, and E). R-package MAD suggested that 50.7% of the nucleated cells had the deletion when ULSAM-340 was 75 years old (B, F, and G) and that when he was 88 years old, the corresponding proportion of cells was 36.1% (C, H, and I). qPCR validation experiments showed that the sample taken when the patient was 88 years old contained 14.5% fewer copies of DNA in the segment as compared to the sample taken when he was 75 years old (Figure 5). The deviations from 0.5 of the BAF values within the deleted region in the three different sampling stages are illustrated in (J).