22-19480156-A-G

Position:

• chr22-19480156-A-G

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PVS1_Moderate PM2 PP5_Moderate

The NM_003504.5(CDC45):​c.52-2A>G variant causes a splice acceptor change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,716 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: 6.8e-7 (0 hom.)
• Consequence: CDC45 NM_003504.5 splice_acceptor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 3.11

Genes affected

CDC45 (HGNC:1739): (cell division cycle 45) The protein encoded by this gene was identified by its strong similarity with Saccharomyces cerevisiae Cdc45, an essential protein required to the initiation of DNA replication. Cdc45 is a member of the highly conserved multiprotein complex including Cdc6/Cdc18, the minichromosome maintenance proteins (MCMs) and DNA polymerase, which is important for early steps of DNA replication in eukaryotes. This protein has been shown to interact with MCM7 and DNA polymerase alpha. Studies of the similar gene in Xenopus suggested that this protein play a pivotal role in the loading of DNA polymerase alpha onto chromatin. Alternate splicing results in multiple transcript variants. [provided by RefSeq, Jul 2013]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.034685478 fraction of the gene. Cryptic splice site detected, with MaxEntScore 3.8, offset of -22, new splice context is: gttcgggtcgccgtgttcAGccg. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 22-19480156-A-G is Pathogenic according to our data. Variant chr22-19480156-A-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 2113883.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CDC45	NM_003504.5	c.52-2A>G		splice_acceptor_variant		ENST00000263201.7	NP_003495.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CDC45	ENST00000263201.7	c.52-2A>G		splice_acceptor_variant		1	NM_003504.5	ENSP00000263201	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461716 Hom.: 0 Cov.: 34 AF XY: 0.00 AC XY: 0 AN XY: 727188

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Mar 18, 2022

In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. This variant has not been reported in the literature in individuals affected with CDC45-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change affects an acceptor splice site in intron 1 of the CDC45 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in CDC45 are known to be pathogenic (PMID: 27374770, 30986546). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.19	D
BayesDel_noAF	Uncertain	0.040
CADD	Pathogenic	27
DANN	Uncertain	0.99
Eigen	Pathogenic	0.98
Eigen_PC	Pathogenic	0.83
FATHMM_MKL	Benign	0.53	D
MutationTaster	Benign	1.0	D;D;D;D
GERP RS		6.0

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.95		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.95		Position offset: 2

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr22-19467679;