rs1557091675

Variant names:

• chrX-153868122-C-T
• rs1557091675
• NM_001278116.2:c.1704G>A

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 2P and 3B. PM2 BP4_Moderate BP7

The NM_001278116.2(L1CAM):​c.1704G>A​(p.Lys568Lys) variant causes a splice region, synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000911 in 1,097,168 control chromosomes in the GnomAD database, with no homozygous occurrence. There are no hemizygote samples in GnomAD. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 23)
  • Exomes 𝑓: 9.1e-7 (0 hom. 0 hem.)
• Consequence: L1CAM NM_001278116.2 splice_region, synonymous
• Scores: Splicing: ADA: 0.9216
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.57
• Publications: 0 publications found

Genes affected

L1CAM (HGNC:6470): (L1 cell adhesion molecule) The protein encoded by this gene is an axonal glycoprotein belonging to the immunoglobulin supergene family. The ectodomain, consisting of several immunoglobulin-like domains and fibronectin-like repeats (type III), is linked via a single transmembrane sequence to a conserved cytoplasmic domain. This cell adhesion molecule plays an important role in nervous system development, including neuronal migration and differentiation. Mutations in the gene cause X-linked neurological syndromes known as CRASH (corpus callosum hypoplasia, retardation, aphasia, spastic paraplegia and hydrocephalus). Alternative splicing of this gene results in multiple transcript variants, some of which include an alternate exon that is considered to be specific to neurons. [provided by RefSeq, May 2013]

L1CAM Gene-Disease associations (from GenCC):

• L1 syndrome

  Inheritance: XL Classification: DEFINITIVE Submitted by: ClinGen
• X-linked hydrocephalus with stenosis of the aqueduct of Sylvius

  Inheritance: XL Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Orphanet, Genomics England PanelApp
• MASA syndrome

  Inheritance: XL Classification: STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet
• X-linked complicated corpus callosum dysgenesis

  Inheritance: XL Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
• X-linked complicated spastic paraplegia type 1

  Inheritance: XL Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_benign. The variant received -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (REVEL=0.065).
• BP7: Synonymous conserved (PhyloP=1.57 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001278116.2. 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
	L1CAM	NM_001278116.2	MANE Select	c.1704G>A	p.Lys568Lys	splice_region synonymous	Exon 15 of 29	NP_001265045.1	P32004-1
	L1CAM	NM_000425.5		c.1704G>A	p.Lys568Lys	splice_region synonymous	Exon 14 of 28	NP_000416.1	P32004-1
	L1CAM	NM_024003.3		c.1704G>A	p.Lys568Lys	splice_region synonymous	Exon 14 of 27	NP_076493.1	P32004-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	L1CAM	ENST00000370060.7	TSL:5 MANE Select	c.1704G>A	p.Lys568Lys	splice_region synonymous	Exon 15 of 29	ENSP00000359077.1	P32004-1
	L1CAM	ENST00000361699.8	TSL:1	c.1704G>A	p.Lys568Lys	splice_region synonymous	Exon 14 of 27	ENSP00000355380.4	P32004-2
	L1CAM	ENST00000361981.7	TSL:1	c.1689G>A	p.Lys563Lys	splice_region synonymous	Exon 13 of 26	ENSP00000354712.3	P32004-3

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome AF: 9.11e-7 AC: 1 AN: 1097168 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 362740

African (AFR) AF: 0.00 AC: 0 AN: 26398

American (AMR) AF: 0.00 AC: 0 AN: 35200

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 19384

East Asian (EAS) AF: 0.00 AC: 0 AN: 30201

South Asian (SAS) AF: 0.00 AC: 0 AN: 54137

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 39626

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4136

European-Non Finnish (NFE) AF: 0.00000119 AC: 1 AN: 842004

Other (OTH) AF: 0.00 AC: 0 AN: 46082

GnomAD4 genome Cov.: 23

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, single submitter

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

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.31
CADD	Benign	18
DANN	Benign	0.78
PhyloP100		1.6
PromoterAI		0.0084	Neutral

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.92
dbscSNV1_RF	Benign	0.63
SpliceAI score (max)		0.17		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: rs1557091675; hg19: chrX-153133577;