chr4-80202687-G-A

Position:

• chr4-80202687-G-A

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_001099403.2(PRDM8):​c.1225G>A​(p.Val409Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 14/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: PRDM8 NM_001099403.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.0470

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]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.06077233).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PRDM8	NM_001099403.2	c.1225G>A	p.Val409Ile	missense_variant	4/4	ENST00000415738.3
PRDM8	NM_020226.4	c.1225G>A	p.Val409Ile	missense_variant	10/10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PRDM8	ENST00000415738.3	c.1225G>A	p.Val409Ile	missense_variant	4/4	1	NM_001099403.2	P1
PRDM8	ENST00000339711.8	c.1225G>A	p.Val409Ile	missense_variant	10/10	1		P1
PRDM8	ENST00000515013.5	c.1225G>A	p.Val409Ile	missense_variant	10/10	1
PRDM8	ENST00000504452.5	c.1225G>A	p.Val409Ile	missense_variant	8/8	5		P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1259152 Hom.: 0 Cov.: 36 AF XY: 0.00 AC XY: 0 AN XY: 612288

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Early-onset Lafora body disease Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Apr 16, 2017

In summary, this variant is a novel missense change that is not predicted to affect protein function. There is no indication that it causes disease, but the available evidence is currently insufficient to prove that conclusively. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but these predictions have not been confirmed by published functional studies. While this variant is not present in population databases, the frequency information is unreliable, as metrics indicate poor data quality at this position in the ExAC database. This variant has not been reported in the literature in individuals with a PRDM8-related disease. This sequence change replaces valine with isoleucine at codon 409 of the PRDM8 protein (p.Val409Ile). The valine residue is weakly conserved and there is a small physicochemical difference between valine and isoleucine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.086
BayesDel_addAF	Benign	-0.19	T
BayesDel_noAF	Benign	-0.50
CADD	Benign	2.7
DANN	Benign	0.96
DEOGEN2	Benign	0.011	T;.;T;T
Eigen	Benign	-0.97
Eigen_PC	Benign	-0.95
FATHMM_MKL	Benign	0.024	N
LIST_S2	Benign	0.40	.;T;T;.
M_CAP	Uncertain	0.20	D
MetaRNN	Benign	0.061	T;T;T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	0.0	N;.;N;N
MutationTaster	Benign	1.0	N;N;N
PrimateAI	Pathogenic	0.89	D
PROVEAN	Benign	-0.21	N;N;N;N
REVEL	Benign	0.053
Sift	Benign	0.83	T;D;T;T
Sift4G	Benign	0.10	T;T;T;T
Polyphen		0.023	B;.;B;B
Vest4		0.041
MutPred		0.091		Loss of catalytic residue at V409 (P = 0.0968);Loss of catalytic residue at V409 (P = 0.0968);Loss of catalytic residue at V409 (P = 0.0968);Loss of catalytic residue at V409 (P = 0.0968);
MVP		0.34
ClinPred		0.041	T
GERP RS		1.2
Varity_R		0.025
gMVP		0.035

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs1483533129; hg19: chr4-81123841;