chr13-101107613-G-A

Variant names:

• chr13-101107613-G-A
• rs200652639
• NM_052867.4:c.2457-4C>T

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_052867.4(NALCN):​c.2457-4C>T variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,756 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: NALCN NM_052867.4 splice_region, intron
• Scores: Splicing: ADA: 0.0001364
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.337
• Publications: 1 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 Gene-Disease associations (from GenCC):

• congenital contractures of the limbs and face, hypotonia, and developmental delay

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
• hypotonia, infantile, with psychomotor retardation and characteristic facies 1

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae)
• digitotalar dysmorphism

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Freeman-Sheldon syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Sheldon-hall syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• hypotonia, infantile, with psychomotor retardation and characteristic facies

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• temporal lobe epilepsy

  Inheritance: AD Classification: LIMITED Submitted by: G2P

ACMG classification

Our verdict: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.75).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NALCN	NM_052867.4	c.2457-4C>T		splice_region_variant, intron_variant	Intron 21 of 43	ENST00000251127.11	NP_443099.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NALCN	ENST00000251127.11	c.2457-4C>T		splice_region_variant, intron_variant	Intron 21 of 43	1	NM_052867.4	ENSP00000251127.6

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461756 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727178

African (AFR) AF: 0.00 AC: 0 AN: 33476

American (AMR) AF: 0.00 AC: 0 AN: 44714

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39694

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111912

Other (OTH) AF: 0.00 AC: 0 AN: 60386

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.75
CADD	Benign	3.5
DANN	Benign	0.62
PhyloP100		0.34
Mutation Taster		=96/4	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.00014
dbscSNV1_RF	Benign	0.014
SpliceAI score (max)		0.050		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: rs200652639; hg19: chr13-101759964;