chr13-101055399-G-T

Variant names:

• chr13-101055399-G-T
• rs779310313
• NM_052867.4:c.5113C>A

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 3P and 2B. PM2 PP2 BP4_Moderate

The NM_052867.4(NALCN):​c.5113C>A​(p.Pro1705Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,864 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 (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P1705S) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: NALCN NM_052867.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.63
• Publications: 0 publications found

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

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• 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=0.21432772).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_052867.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	NALCN	NM_052867.4	MANE Select	c.5113C>A	p.Pro1705Thr	missense	Exon 44 of 44	NP_443099.1	Q8IZF0-1
	NALCN	NM_001350748.2		c.5200C>A	p.Pro1734Thr	missense	Exon 45 of 45	NP_001337677.1	A0A6Q8PFS9
	NALCN	NM_001350749.2		c.5113C>A	p.Pro1705Thr	missense	Exon 44 of 44	NP_001337678.1	Q8IZF0-1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	NALCN	ENST00000251127.11	TSL:1 MANE Select	c.5113C>A	p.Pro1705Thr	missense	Exon 44 of 44	ENSP00000251127.6	Q8IZF0-1
	NALCN	ENST00000675332.1		c.5200C>A	p.Pro1734Thr	missense	Exon 45 of 45	ENSP00000501955.1	A0A6Q8PFS9
	NALCN	ENST00000858715.1		c.5113C>A	p.Pro1705Thr	missense	Exon 44 of 44	ENSP00000528774.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461864 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727236

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

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: 86256

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: 8.99e-7 AC: 1 AN: 1111988

Other (OTH) AF: 0.00 AC: 0 AN: 60394

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.074
BayesDel_addAF	Pathogenic	0.22	D
BayesDel_noAF	Uncertain	0.080
CADD	Benign	22
DANN	Uncertain	0.99
DEOGEN2	Benign	0.18	T
Eigen	Benign	-0.018
Eigen_PC	Uncertain	0.22
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.94	D
M_CAP	Benign	0.039	D
MetaRNN	Benign	0.21	T
MetaSVM	Uncertain	0.27	D
MutationAssessor	Benign	0.55	N
PhyloP100		7.6
PrimateAI	Uncertain	0.67	T
PROVEAN	Benign	-1.0	N
REVEL	Uncertain	0.40
Sift	Benign	0.14	T
Sift4G	Benign	0.32	T
Polyphen		0.0	B
Vest4		0.45
MutPred		0.30		Gain of catalytic residue at D1708 (P = 0.0012)
MVP		0.54
MPC		0.49
ClinPred		0.78	D
GERP RS		5.4
Varity_R		0.20
gMVP		0.80
Mutation Taster		=67/33	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

Other links and lift over

dbSNP: rs779310313; hg19: chr13-101707751;