13-101055385-C-T

Variant summary

Our verdict is Likely benign. Variant got -6 ACMG points: 0P and 6B. BP4_Strong BP6 BP7

The NM_052867.4(NALCN):c.5127G>A(p.Ala1709=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000039 in 1,614,128 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 Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.000046 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000038 (0 hom.)
• Consequence: NALCN NM_052867.4 synonymous
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:3
• Conservation: PhyloP100: -2.07

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)

ACMG classification

Verdict is Likely_benign. Variant got -6 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.65).
• BP6: Variant 13-101055385-C-T is Benign according to our data. Variant chr13-101055385-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 1305297.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=3, Uncertain_significance=1}.
• BP7: Synonymous conserved (PhyloP=-2.07 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
NALCN	NM_052867.4	c.5127G>A	p.Ala1709=	synonymous_variant	44/44	ENST00000251127.11
NALCN-AS1	NR_047687.1	n.709C>T		non_coding_transcript_exon_variant	6/8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
NALCN	ENST00000251127.11	c.5127G>A	p.Ala1709=	synonymous_variant	44/44	1	NM_052867.4	P1
NALCN-AS1	ENST00000457843.1	n.709C>T		non_coding_transcript_exon_variant	6/8	2

Frequencies

GnomAD3 genomes AF: 0.0000329 AC: 5 AN: 152146 Hom.: 0 Cov.: 32

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: 0.0000441

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251436 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135892

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

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: 0.0000383 AC: 56 AN: 1461864 Hom.: 0 Cov.: 31 AF XY: 0.0000371 AC XY: 27 AN XY: 727234

Gnomad4 AFR exome AF: 0.000119

Gnomad4 AMR exome AF: 0.0000447

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000369

Gnomad4 OTH exome AF: 0.000116

GnomAD4 genome AF: 0.0000460 AC: 7 AN: 152264 Hom.: 0 Cov.: 32 AF XY: 0.0000537 AC XY: 4 AN XY: 74458

Gnomad4 AFR AF: 0.0000963

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: 0.0000441

Gnomad4 OTH AF: 0.00

Bravo AF: 0.0000151

Asia WGS AF: 0.000577 AC: 2 AN: 3478

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:3

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:1 Benign:2

Likely benign, criteria provided, single submitter	clinical testing	Invitae	Jan 04, 2023	- -
Likely benign, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Feb 01, 2024	NALCN: BP4, BP7 -
Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Apr 23, 2019	Not observed at a significant frequency in large population cohorts (Lek et al., 2016); Has not been previously published as pathogenic or benign to our knowledge; In-silico analysis, which includes splice predictors and evolutionary conservation, is inconclusive as to whether the variant alters gene splicing. In the absence of RNA/functional studies, the actual effect of this sequence change is unknown. -

NALCN-related disorder Benign:1

Likely benign, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Apr 19, 2021

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.65
Cadd	Benign	0.74
Dann	Benign	0.84

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs111638537; hg19: chr13-101707737; COSMIC: COSV99215697;