chr10-14908583-C-CT
Variant summary
Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PVS1_ModerateBS1_SupportingBS2
The NM_001033855.3(DCLRE1C):c.1903dupA(p.Ser635LysfsTer6) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000229 in 1,614,130 control chromosomes in the GnomAD database, including 2 homozygotes. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_001033855.3 frameshift
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Likely_benign. Variant got -3 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.000243 AC: 37AN: 152140Hom.: 0 Cov.: 31
GnomAD3 exomes AF: 0.000398 AC: 100AN: 251198Hom.: 0 AF XY: 0.000472 AC XY: 64AN XY: 135730
GnomAD4 exome AF: 0.000228 AC: 333AN: 1461872Hom.: 2 Cov.: 32 AF XY: 0.000271 AC XY: 197AN XY: 727236
GnomAD4 genome AF: 0.000243 AC: 37AN: 152258Hom.: 0 Cov.: 31 AF XY: 0.000255 AC XY: 19AN XY: 74440
ClinVar
Submissions by phenotype
not provided Uncertain:2
Frameshift variant predicted to result in protein truncation as the last 58 amino acids are lost and replaced with 5 incorrect amino acids, although loss-of-function variants have not been reported downstream of this position in the protein; Observed previously in one patient with breast cancer (Lhota et al., 2016); This variant is associated with the following publications: (PMID: 33206719, 26822949) -
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Severe combined immunodeficiency due to DCLRE1C deficiency Uncertain:1Benign:1
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not specified Uncertain:1
Variant summary: DCLRE1C c.1903dupA (p.Ser635LysfsX6) results in a premature termination codon located in exon 14 (i.e. in the last exon), therefore it is not expected to cause nonsense mediated decay (NMD), but is predicted to cause a truncation of the encoded protein, removing a C-terminal portion of the 692 amino acid long protein. One truncation downstream of this position has been reported in a homozygous individual affected with primary immunodeficiency (PMID: 32888943, through HGMD), however no further evidence details (e.g. phenotype severity) were provided on this case. The variant allele was found at a frequency of 0.0004 in 251198 control chromosomes, predominantly within the Ashkenazi Jewish and South Asian subpopulations with frequencies of 0.0024 and 0.001, respectively, in the gnomAD database (v2.1, exomes dataset). The observed variant frequencies within the Ashkenazi Jewish and South Asian control individuals are approximately 3.4 and 1.4 fold higher (respectively) than the estimated maximal expected allele frequency (MPAF) for a pathogenic variant in DCLRE1C causing Severe Combined Immunodeficiency phenotype (0.00071), suggesting that the variant is a benign polymorphism. In addition, the variant was also reported in the Turkish population in individuals undergoing whole exome- or genome sequencing, who had unrelated phenotypes to the variant, with a frequency of 0.0019, which is about 2.7 fold higher than the MPAF. To our knowledge, no occurrence of c.1903dupA in individuals affected with Severe Combined Immunodeficiency and no experimental evidence demonstrating its impact on protein function have been reported. An in vitro functional study examined several truncations upstream from our variant, and found that they retained relatively high residual activity levels (50-98%), however, no clear correlation was observed with the level of residual activity and the position of the truncations, therefore it is not possible to make clear conclusions about the variant effect for a truncation located a downstream from the examined variants. Authors of this study also noted that the observed hypomorphic effect for C-terminal truncations was consistent with a less severe phenotype in several reported cases who had these variants in homozygous state (PMID: 25917813). Six clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014, mostly without evidence for independent evaluation, and classified the variant as likely benign (n=1) and VUS (n=5). Based on the evidence outlined above, the variant was classified as uncertain significance. -
Severe combined immunodeficiency due to DCLRE1C deficiency;C2700553:Histiocytic medullary reticulosis Uncertain:1
DCLRE1C NM_001033855.2 exon 14 p.Ser635Lysfs*6 (c.1903dupA): This variant has been reported in the literature in 1 individual with breast cancer (Lhota 2016 PMID:26822949). This variant is present in 0.2% (24/10360) of Ashkenazi Jewish alleles in the Genome Aggregation Database (https://gnomad.broadinstitute.org/variant/10-14950582-C-CT?dataset=gnomad_r2_1). This variant is present in ClinVar (Variation ID:468484). Evolutionary conservation and computational predictive tools for this variant are limited or unavailable. This variant is a duplication of 1 nucleotide at position 1903. This variant creates a premature stop codon 6 amino acids downstream from this location which results in an absent or abnormal protein. However, this variant occurs within the last exon of this gene; due to its position, it is possible that this protein may escape nonsense mediated decay. Variants occuring in this region have been reported to retain high activity levels potentially consistent with a less severe phenotype (Felgentreff 2016 PMID: 25917813). Further studies are needed to understand its impact. In summary, data on this variant is insufficient for disease classification. Therefore, the clinical significance of this variant is uncertain. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at