Walne, Amanda J.Collopy, LauraCardoso, ShirlenyEllison, AliciaPlagnol, VincentAlbayrak, CananAlbayrak, DavutPatiroğlu, TürkanAkar, HalukGodfrey, KeithCarter, TinaMarafie, MakiaVora, AjaySundin, MikaelVulliamy, ThomasTummala, HemanthDokal, Inderjeet2022-10-262022-10-262016-06-21Walne, A. J. vd. (2016). "Marked overlap of four genetic syndromes with dyskeratosis congenita confounds clinical diagnosis". Haematologica, 101(10), 1180-1189.0390-6078https://doi.org/10.3324/haematol.2016.147769https://haematologica.org/article/view/7844http://hdl.handle.net/11452/29214Dyskeratosis congenita is a highly pleotropic genetic disorder. This heterogeneity can lead to difficulties in making an accurate diagnosis and delays in appropriate management. The aim of this study was to determine the underlying genetic basis in patients presenting with features of dyskeratosis congenita and who were negative for mutations in the classical dyskeratosis congenita genes. By whole exome and targeted sequencing, we identified biallelic variants in genes that are not associated with dyskeratosis congenita in 17 individuals from 12 families. Specifically, these were homozygous variants in USB1 (8 families), homozygous missense variants in GRHL2 (2 families) and identical compound heterozygous variants in LIG4 (2 families). All patients had multiple somatic features of dyskeratosis congenita but not the characteristic short telomeres. Our case series shows that biallelic variants in USB1, LIG4 and GRHL2, the genes mutated in poikiloderma with neutropenia, LIG4/Dubowitz syndrome and the recently recognized ectodermal dysplasia/short stature syndrome, respectively, cause features that overlap with dyskeratosis congenita. Strikingly, these genes also overlap in their biological function with the known dyskeratosis congenita genes that are implicated in telomere maintenance and DNA repair pathways. Collectively, these observations demonstrate the marked overlap of dyskeratosis congenita with four other genetic syndromes, confounding accurate diagnosis and subsequent management. This has important implications for establishing a genetic diagnosis when a new patient presents in the clinic. Patients with clinical features of dyskeratosis congenita need to have genetic analysis of USB1, LIG4 and GRHL2 in addition to the classical dyskeratosis congenita genes and telomere length measurements.eninfo:eu-repo/semantics/openAccessHematologyBone-marrow failureTelomere biologyPoikilodermaMutationsNeutropeniaC16orf57LengthMaturationFamilyGrhl2DNA ligase ATPDNA-binding proteinsDyskeratosis congenitaExomeGenetic variationHumansPedigreePhosphoric diester hydrolasesSequence analysis, DNASyndromeTranscription factorsArticle0003925487000192-s2.0-84989282799118011891011027612988HematologyDyskeratosis Congenita; Mutation; Telomerase RNAATP dependent DNA ligaseDNA binding proteinGRHL2 protein, humanLIG4 protein, humanPhosphodiesteraseTranscription factorUSB1 protein, human5' untranslated regionArticleCell proliferationDNA repairDyskeratosis congenitaGeneGenetic analysisGenetic disorderGRHL2 geneLIG4 geneNail dystrophyNeutropeniaPoikilodermaPolymerase chain reactionSegregation analysisTelomere homeostasisUSB1 geneDNA sequenceDyskeratosis congenitaExomeGenetic variationGeneticsHumanPedigreeSyndrome