chr20-5954627-TTTGA-T

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1PP5_Moderate

The NM_032485.6(MCM8):​c.278_281delTTGA​(p.Ile93ArgfsTer22) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000028 in 1,608,850 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000024 ( 0 hom. )

Consequence

MCM8
NM_032485.6 frameshift

Scores

Not classified

Clinical Significance

Pathogenic criteria provided, single submitter P:1

Conservation

PhyloP100: 3.44

Publications

0 publications found
Variant links:
Genes affected
MCM8 (HGNC:16147): (minichromosome maintenance 8 homologous recombination repair factor) The protein encoded by this gene is one of the highly conserved mini-chromosome maintenance proteins (MCM) that are essential for the initiation of eukaryotic genome replication. The hexameric protein complex formed by the mini-chromosome maintenance proteins is a key component of the pre-replication complex and may be involved in the formation of replication forks and in the recruitment of other DNA replication related proteins. This protein contains the central domain that is conserved among the mini-chromosome maintenance proteins. The encoded protein may interact with other mini-chromosome maintenance proteins and play a role in DNA replication. This gene may be associated with length of reproductive lifespan and menopause. Alternatively spliced transcript variants encoding distinct isoforms have been described. [provided by RefSeq, Jul 2013]
MCM8 Gene-Disease associations (from GenCC):
  • premature ovarian failure 10
    Inheritance: AR, AD Classification: STRONG, MODERATE, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
  • colorectal cancer
    Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 10 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PP5
Variant 20-5954627-TTTGA-T is Pathogenic according to our data. Variant chr20-5954627-TTTGA-T is described in ClinVar as [Pathogenic]. Clinvar id is 373125.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MCM8NM_032485.6 linkc.278_281delTTGA p.Ile93ArgfsTer22 frameshift_variant Exon 4 of 19 ENST00000610722.4 NP_115874.3 Q9UJA3-1B4DN82

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MCM8ENST00000610722.4 linkc.278_281delTTGA p.Ile93ArgfsTer22 frameshift_variant Exon 4 of 19 1 NM_032485.6 ENSP00000478141.1 Q9UJA3-1
ENSG00000286235ENST00000652720.1 linkc.278_281delTTGA p.Ile93ArgfsTer22 frameshift_variant Exon 4 of 24 ENSP00000498784.1 A0A494C100

Frequencies

GnomAD3 genomes
AF:
0.0000657
AC:
10
AN:
152248
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000207
Gnomad FIN
AF:
0.000847
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000478
AC:
12
AN:
251004
AF XY:
0.0000663
show subpopulations
Gnomad AFR exome
AF:
0.0000616
Gnomad AMR exome
AF:
0.0000290
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.000232
Gnomad NFE exome
AF:
0.00000880
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000240
AC:
35
AN:
1456602
Hom.:
0
AF XY:
0.0000248
AC XY:
18
AN XY:
724944
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33348
American (AMR)
AF:
0.0000224
AC:
1
AN:
44618
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26080
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39652
South Asian (SAS)
AF:
0.0000930
AC:
8
AN:
86042
European-Finnish (FIN)
AF:
0.000150
AC:
8
AN:
53248
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5752
European-Non Finnish (NFE)
AF:
0.0000153
AC:
17
AN:
1107664
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60198
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.429
Heterozygous variant carriers
0
2
4
5
7
9
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000657
AC:
10
AN:
152248
Hom.:
0
Cov.:
32
AF XY:
0.000134
AC XY:
10
AN XY:
74386
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41476
American (AMR)
AF:
0.00
AC:
0
AN:
15284
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5204
South Asian (SAS)
AF:
0.000207
AC:
1
AN:
4834
European-Finnish (FIN)
AF:
0.000847
AC:
9
AN:
10626
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68032
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.480
Heterozygous variant carriers
0
1
2
2
3
4
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.0000151

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

not provided Pathogenic:1
Nov 29, 2016
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.278_281delTTGA variant in the MCM8 gene has not been reported previously as a pathogenic variant nor as a benign variant, to our knowledge. The c.278_281delTTGA variant causes a frameshift starting with codon Isoleucine 93, changes this amino acid to a Arginine residue, and creates a premature Stop codon at position 22 of the new reading frame, denoted p.Ile93ArgfsX22. This variant is predicted to cause loss of normal protein function either through protein truncation or nonsense-mediated mRNA decay. The c.278_281delTTGA variant was not observed in approximately 6500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. We interpret c.278_281delTTGA as a pathogenic variant -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
PhyloP100
3.4
Mutation Taster
=0/200
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
Details are displayed if max score is > 0.2

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

Publications

Other links and lift over

dbSNP: rs777947820; hg19: chr20-5935273; COSMIC: COSV52545124; COSMIC: COSV52545124; API