13-101055386-G-A

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 1P and 4B. PP2BP4_Strong

The NM_052867.4(NALCN):​c.5126C>T​(p.Ala1709Val) variant causes a missense change. The variant allele was found at a frequency of 0.00000743 in 1,614,000 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A1709T) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000068 ( 0 hom. )

Consequence

NALCN
NM_052867.4 missense

Scores

2
17

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 4.21

Publications

0 publications found
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-AS1 (HGNC:42743): (NALCN antisense RNA 1)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -3 ACMG points.

PP2
Missense variant in the NALCN gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 63 curated pathogenic missense variants (we use a threshold of 10). The gene has 9 curated benign missense variants. Gene score misZ: 4.9555 (above the threshold of 3.09). Trascript score misZ: 6.7536 (above the threshold of 3.09). GenCC associations: The gene is linked to congenital contractures of the limbs and face, hypotonia, and developmental delay, temporal lobe epilepsy, hypotonia, infantile, with psychomotor retardation and characteristic facies 1, Sheldon-hall syndrome, digitotalar dysmorphism, hypotonia, infantile, with psychomotor retardation and characteristic facies, Freeman-Sheldon syndrome.
BP4
Computational evidence support a benign effect (MetaRNN=0.057310402).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
NALCNNM_052867.4 linkc.5126C>T p.Ala1709Val missense_variant Exon 44 of 44 ENST00000251127.11 NP_443099.1 Q8IZF0-1A0A024RE05

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
NALCNENST00000251127.11 linkc.5126C>T p.Ala1709Val missense_variant Exon 44 of 44 1 NM_052867.4 ENSP00000251127.6 Q8IZF0-1

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152152
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000483
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000398
AC:
1
AN:
251422
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.0000615
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS 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:
0.00000684
AC:
10
AN:
1461848
Hom.:
0
Cov.:
31
AF XY:
0.00000275
AC XY:
2
AN XY:
727224
show subpopulations
African (AFR)
AF:
0.000119
AC:
4
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39698
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86252
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000540
AC:
6
AN:
1111976
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.535
Heterozygous variant carriers
0
1
2
3
4
5
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152152
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74340
show subpopulations
African (AFR)
AF:
0.0000483
AC:
2
AN:
41422
American (AMR)
AF:
0.00
AC:
0
AN:
15270
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5202
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68028
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.575
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000341
Hom.:
0
Bravo
AF:
0.0000113

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Inborn genetic diseases Uncertain:1
Oct 14, 2020
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.5126C>T (p.A1709V) alteration is located in exon 44 (coding exon 43) of the NALCN gene. This alteration results from a C to T substitution at nucleotide position 5126, causing the alanine (A) at amino acid position 1709 to be replaced by a valine (V). Based on data from the Genome Aggregation Database (gnomAD) database, the NALCN c.5126C>T alteration was observed in 0.0007% (2/282822) of total alleles studied, with a frequency of 0.008% (2/24964) in the African subpopulation. This amino acid position is poorly conserved in available vertebrate species. The p.A1709V alteration is predicted to be tolerated by in silico analysis. Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

not provided Uncertain:1
Sep 17, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 1709 of the NALCN protein (p.Ala1709Val). This variant is present in population databases (rs373221131, gnomAD 0.008%). 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: 2227836). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt NALCN protein function with a negative predictive value of 80%. 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
0.076
BayesDel_addAF
Benign
-0.13
T
BayesDel_noAF
Benign
-0.24
CADD
Benign
17
DANN
Benign
0.93
DEOGEN2
Benign
0.13
T
Eigen
Benign
-0.60
Eigen_PC
Benign
-0.43
FATHMM_MKL
Uncertain
0.87
D
LIST_S2
Benign
0.81
T
M_CAP
Benign
0.044
D
MetaRNN
Benign
0.057
T
MetaSVM
Uncertain
0.17
D
MutationAssessor
Benign
0.0
N
PhyloP100
4.2
PrimateAI
Benign
0.33
T
PROVEAN
Benign
-0.35
N
REVEL
Benign
0.25
Sift
Benign
0.44
T
Sift4G
Benign
0.31
T
Polyphen
0.091
B
Vest4
0.031
MutPred
0.32
Gain of catalytic residue at D1708 (P = 0);
MVP
0.37
MPC
0.44
ClinPred
0.14
T
GERP RS
4.6
Varity_R
0.034
gMVP
0.53
Mutation Taster
=85/15
polymorphism

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

Other links and lift over

dbSNP: rs373221131; hg19: chr13-101707738; COSMIC: COSV105082999; API