chr1-97450058-C-G

Variant names:

• chr1-97450058-C-G
• rs3918290
• NM_000110.4:c.1905+1G>C

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1_Moderate PM2 PP5_Very_Strong

The NM_000110.4(DPYD):​c.1905+1G>C variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,520 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: DPYD NM_000110.4 splice_donor, intron
• Scores: Splicing: ADA: 0.9999
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: 7.57
• Publications: 345 publications found

Genes affected

DPYD (HGNC:3012): (dihydropyrimidine dehydrogenase) The protein encoded by this gene is a pyrimidine catabolic enzyme and the initial and rate-limiting factor in the pathway of uracil and thymidine catabolism. Mutations in this gene result in dihydropyrimidine dehydrogenase deficiency, an error in pyrimidine metabolism associated with thymine-uraciluria and an increased risk of toxicity in cancer patients receiving 5-fluorouracil chemotherapy. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, May 2009]

DPYD Gene-Disease associations (from GenCC):

• dihydropyrimidine dehydrogenase deficiency

  Inheritance: AR Classification: DEFINITIVE Submitted by: G2P

ACMG classification

Our verdict: Pathogenic. The variant received 12 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.05360624 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 1-97450058-C-G is Pathogenic according to our data. Variant chr1-97450058-C-G is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 2429124.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000110.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	DPYD	NM_000110.4	MANE Select	c.1905+1G>C		splice_donor intron	N/A	NP_000101.2

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	DPYD	ENST00000370192.8	TSL:1 MANE Select	c.1905+1G>C		splice_donor intron	N/A	ENSP00000359211.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000796 AC: 2 AN: 251260 AF XY: 0.00000736

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000290

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461520 Hom.: 0 Cov.: 30 AF XY: 0.00000413 AC XY: 3 AN XY: 727054

African (AFR) AF: 0.00 AC: 0 AN: 33468

American (AMR) AF: 0.0000224 AC: 1 AN: 44686

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26118

East Asian (EAS) AF: 0.00 AC: 0 AN: 39678

South Asian (SAS) AF: 0.00 AC: 0 AN: 86254

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53414

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5764

European-Non Finnish (NFE) AF: 0.00000360 AC: 4 AN: 1111764

Other (OTH) AF: 0.00 AC: 0 AN: 60374

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 8

Bravo AF: 0.00000378

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Dihydropyrimidine dehydrogenase deficiency Pathogenic:3

Apr 11, 2023

Genome-Nilou Lab

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Nov 22, 2023

Baylor Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Jan 06, 2023

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: DPYD c.1905+1G>C is located in a canonical splice-site and is predicted to affect mRNA splicing resulting in a significantly altered protein due to either exon skipping, shortening, or inclusion of intronic material. Several computational tools predict a significant impact on normal splicing: Four predict the variant abolishes a canonical 5' splicing donor site. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 8e-06 in 251260 control chromosomes (gnomAD). To our knowledge, no occurrence of c.1905+1G>C in individuals affected with Dihydropyrimidine Dehydrogenase Deficiency and no experimental evidence demonstrating its impact on protein function have been reported. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014. However, a different nucleotide substitution at this position (c.1905+1G>A, ClinVar: 432) is an established pathogenic variant. Based on the evidence outlined above, the variant was classified as likely pathogenic.

not provided Pathogenic:1

Apr 17, 2023

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Canonical splice site variant expected to result in aberrant splicing, although in the absence of functional evidence the actual effect of this sequence change is unknown.; Not observed at significant frequency in large population cohorts (gnomAD); Has not been previously published as pathogenic or benign to our knowledge

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Uncertain	0.080
CADD	Pathogenic	29
DANN	Uncertain	0.99
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.90
FATHMM_MKL	Pathogenic	0.98	D
PhyloP100		7.6
GERP RS		5.3
Mutation Taster		=1/99	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.95
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.99		Position offset: 1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs3918290; hg19: chr1-97915614;