chr13-101229493-A-G

Variant names:

• chr13-101229493-A-G
• rs786203987
• NM_052867.4:c.1526T>C

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PM1 PM2 PP2 PP3_Strong PP5

The NM_052867.4(NALCN):​c.1526T>C​(p.Leu509Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 13/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Pathogenic (no stars).

• Frequency: Genomes: not found (cov: 33)
• Consequence: NALCN NM_052867.4 missense
• Clinical Significance: Pathogenic no assertion criteria provided P:2
• Conservation: PhyloP100: 8.72
• Publications: 5 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: Pathogenic. The variant received 10 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 2 uncertain in NM_052867.4
• 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.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.946
• PP5: Variant 13-101229493-A-G is Pathogenic according to our data. Variant chr13-101229493-A-G is described in ClinVar as Pathogenic. ClinVar VariationId is 187774.Status of the report is no_assertion_criteria_provided, 0 stars.

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

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	NALCN	NM_052867.4	MANE Select	c.1526T>C	p.Leu509Ser	missense	Exon 13 of 44	NP_443099.1
	NALCN	NM_001350748.2		c.1526T>C	p.Leu509Ser	missense	Exon 13 of 45	NP_001337677.1
	NALCN	NM_001350749.2		c.1526T>C	p.Leu509Ser	missense	Exon 13 of 44	NP_001337678.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	NALCN	ENST00000251127.11	TSL:1 MANE Select	c.1526T>C	p.Leu509Ser	missense	Exon 13 of 44	ENSP00000251127.6
	NALCN	ENST00000470333.1	TSL:1	n.1622T>C		non_coding_transcript_exon	Exon 13 of 15
	NALCN	ENST00000675332.1		c.1526T>C	p.Leu509Ser	missense	Exon 13 of 45	ENSP00000501955.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: no assertion criteria provided

Submissions by phenotype

Congenital contractures of the limbs and face, hypotonia, and developmental delay Pathogenic:2

May 19, 2015

University of Washington Center for Mendelian Genomics, University of Washington

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: research

Mar 05, 2015

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.58
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.97	D
Eigen	Pathogenic	0.93
Eigen_PC	Pathogenic	0.85
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.89	D
M_CAP	Pathogenic	0.85	D
MetaRNN	Pathogenic	0.95	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.1	M
PhyloP100		8.7
PrimateAI	Pathogenic	0.86	D
PROVEAN	Pathogenic	-5.3	D
REVEL	Pathogenic	0.98
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.99
MutPred		0.66		Gain of catalytic residue at L509 (P = 0)
MVP		0.83
MPC		2.3
ClinPred		1.0	D
GERP RS		5.1
Varity_R		0.95
gMVP		0.98
Mutation Taster		=0/100	disease causing (ClinVar)

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: rs786203987; hg19: chr13-101881844;