rs1557091675

Positions:

• chrX-153868122-C-T

Variant summary

Our verdict is Likely benign. Variant got -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

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 Likely_benign. Variant got -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.31).
• BP7: Synonymous conserved (PhyloP=1.57 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
L1CAM	NM_001278116.2	c.1704G>A	p.Lys568Lys	splice_region_variant, synonymous_variant	15/29	ENST00000370060.7	NP_001265045.1
L1CAM	NM_000425.5	c.1704G>A	p.Lys568Lys	splice_region_variant, synonymous_variant	14/28		NP_000416.1
L1CAM	NM_024003.3	c.1704G>A	p.Lys568Lys	splice_region_variant, synonymous_variant	14/27		NP_076493.1
L1CAM	NM_001143963.2	c.1689G>A	p.Lys563Lys	splice_region_variant, synonymous_variant	13/26		NP_001137435.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
L1CAM	ENST00000370060.7	c.1704G>A	p.Lys568Lys	splice_region_variant, synonymous_variant	15/29	5	NM_001278116.2	ENSP00000359077.1

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

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000119

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 23

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genetic Services Laboratory, University of Chicago

Sep 07, 2016

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.31
CADD	Benign	18
DANN	Benign	0.78

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

Publications

LitVar

Other links and lift over

dbSNP: rs1557091675; hg19: chrX-153133577;