4-80200198-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_001099403.2(PRDM8):c.118A>G(p.Ile40Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000744 in 1,613,964 control chromosomes in the GnomAD database, with no homozygous occurrence. 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: 𝑓 0.000020 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000062 (0 hom.)
• Consequence: PRDM8 NM_001099403.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.39

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 Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.2456856).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PRDM8	NM_001099403.2	c.118A>G	p.Ile40Val	missense_variant	2/4	ENST00000415738.3
PRDM8	NM_020226.4	c.118A>G	p.Ile40Val	missense_variant	8/10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PRDM8	ENST00000415738.3	c.118A>G	p.Ile40Val	missense_variant	2/4	1	NM_001099403.2	P1
PRDM8	ENST00000339711.8	c.118A>G	p.Ile40Val	missense_variant	8/10	1		P1
PRDM8	ENST00000515013.5	c.118A>G	p.Ile40Val	missense_variant	8/10	1
PRDM8	ENST00000504452.5	c.118A>G	p.Ile40Val	missense_variant	6/8	5		P1

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152160 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000294

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000200 AC: 5 AN: 249584 Hom.: 0 AF XY: 0.0000148 AC XY: 2 AN XY: 135408

Gnomad AFR exome AF: 0.0000646

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000265

Gnomad OTH exome AF: 0.000165

GnomAD4 exome AF: 0.00000616 AC: 9 AN: 1461804 Hom.: 0 Cov.: 31 AF XY: 0.00000688 AC XY: 5 AN XY: 727216

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: 0.00000630

Gnomad4 OTH exome AF: 0.0000331

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152160 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74344

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000294

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000756

ExAC AF: 0.00000827 AC: 1

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

Invitae

Aug 16, 2022

This sequence change replaces isoleucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 40 of the PRDM8 protein (p.Ile40Val). This variant is present in population databases (rs772463473, gnomAD 0.007%). 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: 1475554). 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. 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
AlphaMissense	Benign	0.21
BayesDel_addAF	Benign	-0.19	T
BayesDel_noAF	Benign	-0.32
Cadd	Benign	23
Dann	Uncertain	0.98
DEOGEN2	Benign	0.0086	T;.;T;T
Eigen	Benign	0.12
Eigen_PC	Uncertain	0.24
FATHMM_MKL	Uncertain	0.96	D
M_CAP	Benign	0.020	T
MetaRNN	Benign	0.25	T;T;T;T
MetaSVM	Benign	-0.89	T
MutationAssessor	Benign	-0.65	N;.;N;N
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.57	T
PROVEAN	Benign	-0.44	N;N;N;N
REVEL	Benign	0.24
Sift	Benign	0.20	T;T;T;T
Sift4G	Benign	0.67	T;T;T;T
Polyphen		0.99	D;.;D;D
Vest4		0.50
MVP		0.83
ClinPred		0.24	T
GERP RS		5.4
Varity_R		0.095
gMVP		0.22

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: rs772463473; hg19: chr4-81121352;