Panel a shows chromosome 17 and 20
diagrams with breakpoint 17, breakpoint 20, and the alignment with SAMHD1
exons. Panel b shows proband and healthy donor chromosomes 17 and 20 and
translocation derivatives both as karyotype images on the left and ideogram
cartoons on the right. Panel c shows Western blots for SAMHD1 and Actin
across proband, parental, and healthy donors.
A homozygous translocation between Chr17 and Chr20 results in loss of SAMHD1 expression in the proband. (a) Graphical representation of long-read sequencing reads generated from PBMCs from the proband that cover the breakpoint loci on chromosomes 17 (blue) and 20 (violet). Reads from derivative 17 (der (17), navy lines) and derivative 20 (der (20), green lines) are labeled, as are the loci of the breakpoints (vertical black lines) and alignment to the SAMHD1 gene. (b) Partial G-banding karyotype and corresponding ideograms of chromosomes 17 (blue) and 20 (violet) or their chromosomal derivatives (der) resulting from the translocation from peripheral blood T cells isolated from the proband or healthy controls. (c) Western blot of SAMHD1 and β-actin protein expression in PBMCs from the proband, the father, and healthy donors. (representative of 3 independent blots, * = lower molecular weight isoform of SAMHD1). Source data are available for this figure: SourceData F4.