chr4-80202095-C-CCAG

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 0P and 1B. BP3

The NM_001099403.2(PRDM8):​c.649_651dupCAG​(p.Gln217dup) variant causes a conservative inframe insertion change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000244 in 1,591,500 control chromosomes in the GnomAD database, including 1 homozygotes. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. E218E) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00041 ( 1 hom., cov: 31)
Exomes 𝑓: 0.00023 ( 0 hom. )

Consequence

PRDM8
NM_001099403.2 conservative_inframe_insertion

Scores

Not classified

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: -0.336

Publications

2 publications found
Variant links:
Genes affected
PRDM8 (HGNC:13993): (PR/SET domain 8) This gene encodes a protein that belongs to a conserved family of histone methyltransferases that predominantly act as negative regulators of transcription. The encoded protein contains an N-terminal Su(var)3-9, Enhancer-of-zeste, and Trithorax (SET) domain and a double zinc-finger domain. Knockout of this gene in mouse results in mistargeting by neurons of the dorsal telencephalon, abnormal itch-like behavior, and impaired differentiation of rod bipolar cells. In humans, the protein has been shown to interact with the phosphatase laforin and the ubiquitin ligase malin, which regulate glycogen construction in the cytoplasm. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Feb 2016]
PRDM8 Gene-Disease associations (from GenCC):
  • early-onset Lafora body disease
    Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -1 ACMG points.

BP3
Nonframeshift variant in repetitive region in NM_001099403.2

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
PRDM8NM_001099403.2 linkc.649_651dupCAG p.Gln217dup conservative_inframe_insertion Exon 4 of 4 ENST00000415738.3 NP_001092873.1 Q9NQV8-1A0A024RDC4Q05CA1
PRDM8NM_020226.4 linkc.649_651dupCAG p.Gln217dup conservative_inframe_insertion Exon 10 of 10 NP_064611.3 Q9NQV8-1A0A024RDC4Q05CA1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
PRDM8ENST00000415738.3 linkc.649_651dupCAG p.Gln217dup conservative_inframe_insertion Exon 4 of 4 1 NM_001099403.2 ENSP00000406998.2 Q9NQV8-1
PRDM8ENST00000339711.8 linkc.649_651dupCAG p.Gln217dup conservative_inframe_insertion Exon 10 of 10 1 ENSP00000339764.4 Q9NQV8-1
PRDM8ENST00000515013.5 linkc.649_651dupCAG p.Gln217dup conservative_inframe_insertion Exon 10 of 10 1 ENSP00000425149.1 E9PEH0
PRDM8ENST00000504452.5 linkc.649_651dupCAG p.Gln217dup conservative_inframe_insertion Exon 8 of 8 5 ENSP00000423985.1 Q9NQV8-1

Frequencies

GnomAD3 genomes
AF:
0.000407
AC:
55
AN:
135104
Hom.:
1
Cov.:
31
show subpopulations
Gnomad AFR
AF:
0.000140
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.000229
Gnomad SAS
AF:
0.000483
Gnomad FIN
AF:
0.000912
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000627
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000351
AC:
77
AN:
219640
AF XY:
0.000317
show subpopulations
Gnomad AFR exome
AF:
0.0000741
Gnomad AMR exome
AF:
0.000507
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.000882
Gnomad NFE exome
AF:
0.000360
Gnomad OTH exome
AF:
0.000382
GnomAD4 exome
AF:
0.000229
AC:
334
AN:
1456292
Hom.:
0
Cov.:
39
AF XY:
0.000244
AC XY:
177
AN XY:
724444
show subpopulations
African (AFR)
AF:
0.000120
AC:
4
AN:
33320
American (AMR)
AF:
0.000385
AC:
17
AN:
44166
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25938
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39470
South Asian (SAS)
AF:
0.000501
AC:
43
AN:
85768
European-Finnish (FIN)
AF:
0.000641
AC:
34
AN:
53020
Middle Eastern (MID)
AF:
0.000174
AC:
1
AN:
5748
European-Non Finnish (NFE)
AF:
0.000198
AC:
220
AN:
1108766
Other (OTH)
AF:
0.000250
AC:
15
AN:
60096
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.468
Heterozygous variant carriers
0
23
46
69
92
115
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
10
20
30
40
50
<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:
0.000407
AC:
55
AN:
135208
Hom.:
1
Cov.:
31
AF XY:
0.000303
AC XY:
20
AN XY:
66056
show subpopulations
African (AFR)
AF:
0.000140
AC:
5
AN:
35704
American (AMR)
AF:
0.00
AC:
0
AN:
13910
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3242
East Asian (EAS)
AF:
0.000230
AC:
1
AN:
4350
South Asian (SAS)
AF:
0.000483
AC:
2
AN:
4138
European-Finnish (FIN)
AF:
0.000912
AC:
8
AN:
8776
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
178
European-Non Finnish (NFE)
AF:
0.000627
AC:
39
AN:
62238
Other (OTH)
AF:
0.00
AC:
0
AN:
1866
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.482
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

Genome Het
Genome Hom
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:
0.00107
Hom.:
0

ClinVar

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

Submissions by phenotype

Early-onset Lafora body disease Uncertain:1
Oct 25, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant, c.649_651dup, results in the insertion of 1 amino acid(s) of the PRDM8 protein (p.Gln217dup), but otherwise preserves the integrity of the reading frame. This variant is present in population databases (rs769916001, gnomAD 0.08%), and has an allele count higher than expected for a pathogenic variant. This variant has not been reported in the literature in individuals affected with PRDM8-related conditions. ClinVar contains an entry for this variant (Variation ID: 475682). Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
PhyloP100
-0.34
Mutation Taster
=90/10
polymorphism

Splicing

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

Publications

Other links and lift over

dbSNP: rs748593482; hg19: chr4-81123249; API