{"type": "root", "children": [{"type": "p", "children": [{"type": "t", "text": "\nIn myelodysplastic syndromes (MDS), deletions at chromosome 5q31.2 are frequent and affect a cluster of 28 genes, one of which is SNORD63, a small nucleolar RNA (snoRNA) belonging to the Box C/D family. SnoRNAs like SNORD63 typically guide site‐specific 2′-O-methylation of ribosomal RNA, a process critical for proper rRNA processing, stability, and ribosome assembly, thereby influencing protein synthesis in hematopoietic cells."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "1"}]}, {"type": "t", "text": ""}, {"type": "p", "children": [{"type": "t", "text": "\nThe study assessed both coding and noncoding genes in the deleted region of 5q31.2 and demonstrated that individual point mutations or microdeletions were uncommon; instead, a 50% reduction in expression (haploinsufficiency) was observed for multiple genes in del(5q) MDS samples. This reduction in dose includes noncoding elements like SNORD63, suggesting that insufficient SNORD63 levels may impair the critical 2′-O-methylation events required for efficient rRNA modification and ribosome function."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "1"}]}, {"type": "t", "text": ""}, {"type": "p", "children": [{"type": "t", "text": "\nWhile no complete loss of expression or somatic mutations of SNORD63 were detected, its diminished expression as part of the broader multi-gene haploinsufficiency in the 5q31.2 deletion region may contribute collectively to the pathogenesis of MDS. In this context, the reduced function of SNORD63 likely exacerbates defects in ribosome biogenesis and cellular protein synthesis, thereby playing a role in the complex molecular mechanism underlying the disease."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "1"}]}]}]}]}, {"type": "rg", "children": [{"type": "r", "ref": 1, "children": [{"type": "t", "text": "Timothy A Graubert, Michelle A Payton, Jin Shao, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Integrated genomic analysis implicates haploinsufficiency of multiple chromosome 5q31.2 genes in de novo myelodysplastic syndromes pathogenesis."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "PLoS One (2009)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1371/journal.pone.0004583"}], "href": "https://doi.org/10.1371/journal.pone.0004583"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "19240791"}], "href": "https://pubmed.ncbi.nlm.nih.gov/19240791"}]}]}]}