chr6-18121916-C-T

Position:

• chr6-18121916-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_198586.3(NHLRC1):​c.691G>A​(p.Val231Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,878 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: NHLRC1 NM_198586.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.95

Genes affected

NHLRC1 (HGNC:21576): (NHL repeat containing E3 ubiquitin protein ligase 1) The protein encoded by this gene is a single subunit E3 ubiquitin ligase. Laforin is polyubiquitinated by the encoded protein. Defects in this intronless gene lead to an accumulation of laforin and onset of Lafora disease, also known as progressive myoclonic epilepsy type 2 (EPM2).[provided by RefSeq, Mar 2010]

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.3343091).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
NHLRC1	NM_198586.3	c.691G>A	p.Val231Ile	missense_variant	1/1	ENST00000340650.6	NP_940988.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
NHLRC1	ENST00000340650.6	c.691G>A	p.Val231Ile	missense_variant	1/1	6	NM_198586.3	ENSP00000345464.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461878 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727240

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: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Lafora disease Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 20, 2019

In summary, this variant is a novel missense change with uncertain impact on protein function. 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 disruptive, but these predictions have not been confirmed by published functional studies. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a NHLRC1-related disease. This sequence change replaces valine with isoleucine at codon 231 of the NHLRC1 protein (p.Val231Ile). The valine residue is highly 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	0.092
BayesDel_addAF	Uncertain	0.013	T
BayesDel_noAF	Benign	-0.22
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Benign	0.18	T
Eigen	Benign	-0.40
Eigen_PC	Benign	-0.38
FATHMM_MKL	Uncertain	0.78	D
LIST_S2	Benign	0.57	T
M_CAP	Benign	0.070	D
MetaRNN	Benign	0.33	T
MetaSVM	Uncertain	0.084	D
MutationAssessor	Uncertain	2.5	M
PrimateAI	Benign	0.43	T
PROVEAN	Benign	-0.97	N
REVEL	Uncertain	0.36
Sift	Uncertain	0.015	D
Sift4G	Uncertain	0.059	T
Polyphen		0.016	B
Vest4		0.35
MutPred		0.67		Gain of sheet (P = 0.1945);
MVP		0.83
MPC		0.70
ClinPred		0.85	D
GERP RS		4.1
Varity_R		0.11
gMVP		0.66

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: rs1060503098; hg19: chr6-18122147;