case_images: PMC11347319_01
case_images: Case 1: (A) X-ray images of proband 1 at the age of 8, 10, and 11 years. Multiple osteochondromas around the knee and on the femur are shown. (B) Alignment of the deletion of exons 8-11 in the EXT1 gene in the UCSC browser was found. (C) GS data on mosaic gross deletion from case 1 visualized in the IGV browser. (D) Chromatogram showing the region encompassing the breakpoints of the deletion, with a red line marking the borders of the deletion.
case_images: fgene-15-1435493-g001.jpg
case_images: PMC11347319_01_fgene-15-1435493-g001.jpg
case_images: F1
case_images: Radiography of the knee, hip joints, and upper extremities at the age of 8-11 years revealed multiple osteochondromas in the popliteal fossa, distal part of the ulna, and around the hip joint (Figure 1A). Subsequent GS was performed, which identified a mosaic deletion of chr8:118780297-118828217del (4/40 = 10.0% of the total read count) involving exons 8-11 of the EXT1 gene (Figures 1B, C). This finding was further confirmed by Sanger sequencing (Figure 1D).
case_images: Case 2. (A) Alignment of all deletion of exons 2-11 in the EXT1 gene with known breakpoint borders on the UCSC browser from the literature and case 2 from the current study. Red:germline CNVs; dark red:mosaic CNVs; black:deletion found in the present study. (B) GS data on mosaic gross deletion from case 2 visualized in the IGV browser. (C) Chromatogram showing the region encompassing the breakpoints of the deletion, with a red line marking the borders of the deletion.
case_images: fgene-15-1435493-g002.jpg
case_images: PMC11347319_01_fgene-15-1435493-g002.jpg
case_images: F2
case_images: After negative results of gene panel sequencing and MLPA, GS was performed and revealed mosaic gross deletion of chr8:118798015_118893064del affecting exons 2-11 in the EXT1 gene (5/43 = 11.6% of the total read count) (Figures 2A, B). Deletion was confirmed by Sanger sequencing (Figure 2C).