13-101055425-A-G

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 1P and 2B. PP2BP4_Moderate

The NM_052867.4(NALCN):c.5087T>C(p.Met1696Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000558 in 1,614,006 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000055 ( 0 hom. )

Consequence

NALCN
NM_052867.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 8.95

Variant links:

Genes affected

NALCN (HGNC:19082): (sodium leak channel, non-selective) This gene encodes a voltage-independent, nonselective cation channel which belongs to a family of voltage-gated sodium and calcium channels that regulates the resting membrane potential and excitability of neurons. This family is expressed throughout the nervous system and conducts a persistent sodium leak current that contributes to tonic neuronal excitability. The encoded protein forms a channelosome complex that includes G-protein-coupled receptors, UNC-79, UNC-80, NCA localization factor-1, and src family tyrosine kinases. Naturally occurring mutations in this gene are associated with infantile neuroaxonal dystrophy, infantile hypotonia with psychomotor retardation and characteristic facies (IHPRF) syndrome, and congenital contractures of the limbs and face with hypotonia and developmental delay (CLIFAHDD) syndrome. A knockout of the orthologous gene in mice results in paralysis with a severely disrupted respiratory rhythm, and lethality within 24 hours after birth. [provided by RefSeq, Apr 2017]

NALCN links:

NALCN-AS1 (HGNC:42743): (NALCN antisense RNA 1)

NALCN-AS1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -1 ACMG points.

PP2

Missense variant where missense usually causes diseases, NALCN

BP4

Computational evidence support a benign effect (MetaRNN=0.20308968).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
NALCN	NM_052867.4 linkuse as main transcript	c.5087T>C	p.Met1696Thr	missense_variant	44/44	ENST00000251127.11
NALCN-AS1	NR_047687.1 linkuse as main transcript	n.749A>G		non_coding_transcript_exon_variant	6/8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
NALCN	ENST00000251127.11 linkuse as main transcript	c.5087T>C	p.Met1696Thr	missense_variant	44/44	1	NM_052867.4	P1	Q8IZF0-1
NALCN-AS1	ENST00000457843.1 linkuse as main transcript	n.749A>G		non_coding_transcript_exon_variant	6/8	2

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152140

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000278

AC:

AN:

251462

Hom.:

AF XY:

0.0000147

AC XY:

AN XY:

135896

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000202

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:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000547

AC:

AN:

1461866

Hom.:

Cov.:

AF XY:

0.00000275

AC XY:

AN XY:

727238

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.000179

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

AF:

0.00000657

AC:

AN:

152140

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74322

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.0000655

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000712

Hom.:

Bravo

AF:

0.0000302

ExAC

AF:

0.0000247

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	May 09, 2022	In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -
Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Oct 13, 2023	This sequence change replaces methionine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 1696 of the NALCN protein (p.Met1696Thr). This variant is present in population databases (rs758520457, gnomAD 0.02%). This variant has not been reported in the literature in individuals affected with NALCN-related conditions. ClinVar contains an entry for this variant (Variation ID: 1723722). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt NALCN protein function. 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. -

not specified

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Dec 19, 2023

Variant summary: NALCN c.5087T>C (p.Met1696Thr) results in a non-conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 2.8e-05 in 251462 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.5087T>C in individuals affected with Congenital Contractures Of The Limbs And Face, Hypotonia, And Developmental Delay and no experimental evidence demonstrating its impact on protein function have been reported. Two submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. All submitters classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.14

BayesDel_addAF

Benign

-0.024

BayesDel_noAF

Uncertain

0.010

Cadd

Benign

Dann

Benign

0.93

DEOGEN2

Benign

0.16

Eigen

Benign

-0.15

Eigen_PC

Benign

0.070

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Benign

0.68

M_CAP

Benign

0.054

MetaRNN

Benign

0.20

MetaSVM

Uncertain

0.29

MutationAssessor

Benign

0.34

MutationTaster

Benign

1.0

PrimateAI

Uncertain

0.63

PROVEAN

Benign

-0.69

REVEL

Uncertain

0.41

Sift

Benign

0.24

Sift4G

Benign

0.33

Polyphen

0.0

Vest4

0.46

MutPred

0.52

Gain of catalytic residue at K1697 (P = 0);

MVP

0.54

MPC

0.51

ClinPred

0.15

GERP RS

5.4

Varity_R

0.12

gMVP

0.32

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over