chr6-18122014-A-T

Position:

• chr6-18122014-A-T

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM2 PP3_Strong PP5_Moderate

The NM_198586.3(NHLRC1):​c.593T>A​(p.Ile198Asn) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: NHLRC1 NM_198586.3 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:2 O:1
• Conservation: PhyloP100: 8.54

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 Likely_pathogenic. Variant got 8 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.976
• PP5: Variant 6-18122014-A-T is Pathogenic according to our data. Variant chr6-18122014-A-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 2591.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
NHLRC1	NM_198586.3	c.593T>A	p.Ile198Asn	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.593T>A	p.Ile198Asn	missense_variant	1/1		NM_198586.3	ENSP00000345464	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2 Other:1

Revision: criteria provided, single submitter

Submissions by phenotype

Myoclonic epilepsy of Lafora 2 Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Mar 22, 2005

- -

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Genetic Services Laboratory, University of Chicago

Oct 10, 2019

DNA sequence analysis of the NHLRC1 gene demonstrated a sequence change, c.593T>A, in exon 1 that results in an amino acid change, p.Ile198Asn. This sequence change has been previously described in two symptomatic family members diagnosed with Lafora disease (PMID: 15781812). This sequence change is absent from the population databases (ExAC and gnomAD). The p.Arg22Gln change affects a moderately conserved amino acid residue located in a domain of the CEP104 protein that is known to be functional. The p.Arg22Gln substitution appears to be deleterious using several in-silico pathogenicity prediction tools (SIFT, PolyPhen2, Align GVGD, REVEL). These collective evidences indicate that this sequence change is likely pathogenic; however functional studies have not been performed to prove this conclusively. -

Lafora disease Other:1

not provided, no classification provided

literature only

GeneReviews

-

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.94
BayesDel_addAF	Pathogenic	0.23	D
BayesDel_noAF	Uncertain	0.10
CADD	Pathogenic	27
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.77	D
Eigen	Uncertain	0.35
Eigen_PC	Uncertain	0.44
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Benign	0.81	T
M_CAP	Uncertain	0.14	D
MetaRNN	Pathogenic	0.98	D
MetaSVM	Uncertain	0.30	D
MutationAssessor	Benign	1.8	L
MutationTaster	Benign	1.0	A
PrimateAI	Benign	0.40	T
PROVEAN	Pathogenic	-6.1	D
REVEL	Pathogenic	0.71
Sift	Uncertain	0.0010	D
Sift4G	Uncertain	0.0030	D
Polyphen		0.68	P
Vest4		0.69
MutPred		0.92		Loss of stability (P = 0.02);
MVP		0.93
MPC		1.2
ClinPred		0.99	D
GERP RS		5.0
Varity_R		0.86
gMVP		0.93

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.13		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: rs121917876; hg19: chr6-18122245;