rs878853099

Positions:

• chrX-153869936-T-C

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PVS1_Moderate PM2 PP3_Strong PP5_Moderate

The NM_001278116.2(L1CAM):​c.992-2A>G variant causes a splice acceptor change. The variant was absent in control chromosomes in GnomAD project. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency: Genomes: not found (cov: 24)
• Consequence: L1CAM NM_001278116.2 splice_acceptor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 5.77

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]

ACMG classification

Verdict is Pathogenic. Variant got 10 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.034711182 fraction of the gene. Cryptic splice site detected, with MaxEntScore 3.1, offset of -23, new splice context is: gctgctggctgcgggctcAGggc. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant X-153869936-T-C is Pathogenic according to our data. Variant chrX-153869936-T-C is described in ClinVar as [Pathogenic]. Clinvar id is 235709.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
L1CAM	NM_001278116.2	c.992-2A>G		splice_acceptor_variant		ENST00000370060.7
L1CAM	NM_000425.5	c.992-2A>G		splice_acceptor_variant
L1CAM	NM_001143963.2	c.977-2A>G		splice_acceptor_variant
L1CAM	NM_024003.3	c.992-2A>G		splice_acceptor_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
L1CAM	ENST00000370060.7	c.992-2A>G		splice_acceptor_variant		5	NM_001278116.2	A1
L1CAM	ENST00000361699.8	c.992-2A>G		splice_acceptor_variant		1		P4
L1CAM	ENST00000361981.7	c.977-2A>G		splice_acceptor_variant		1		A1
L1CAM	ENST00000370055.5	c.977-2A>G		splice_acceptor_variant		5		A1

Frequencies

GnomAD3 genomes Cov.: 24

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 24

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Center for Pediatric Genomic Medicine, Children's Mercy Hospital and Clinics

Feb 03, 2015

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Uncertain	0.12	D
BayesDel_noAF	Uncertain	-0.070
CADD	Uncertain	25
DANN	Uncertain	0.98
FATHMM_MKL	Uncertain	0.95	D
MutationTaster	Benign	1.0	D;D;D;D;D;D;D
GERP RS		5.8

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.86
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.40		Position offset: -25
DS_AL_spliceai		0.99		Position offset: -2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs878853099; hg19: chrX-153135391;