chrX-154352449-T-G

Position:

• chrX-154352449-T-G

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PVS1_Moderate PM2 PP5_Moderate

The NM_001110556.2(FLNA):​c.6503-2A>C variant causes a splice acceptor, intron 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. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency: Genomes: not found (cov: 25)
• Consequence: FLNA NM_001110556.2 splice_acceptor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 7.93

Genes affected

FLNA (HGNC:3754): (filamin A) The protein encoded by this gene is an actin-binding protein that crosslinks actin filaments and links actin filaments to membrane glycoproteins. The encoded protein is involved in remodeling the cytoskeleton to effect changes in cell shape and migration. This protein interacts with integrins, transmembrane receptor complexes, and second messengers. Defects in this gene are a cause of several syndromes, including periventricular nodular heterotopias (PVNH1, PVNH4), otopalatodigital syndromes (OPD1, OPD2), frontometaphyseal dysplasia (FMD), Melnick-Needles syndrome (MNS), and X-linked congenital idiopathic intestinal pseudoobstruction (CIIPX). Two transcript variants encoding different isoforms have been found for this gene.[provided by RefSeq, Mar 2009]

FLNA (HGNC:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.033484392 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant X-154352449-T-G is Pathogenic according to our data. Variant chrX-154352449-T-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 405448.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
FLNA	NM_001110556.2	c.6503-2A>C		splice_acceptor_variant, intron_variant		ENST00000369850.10	NP_001104026.1
FLNA	NM_001456.4	c.6479-2A>C		splice_acceptor_variant, intron_variant			NP_001447.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
FLNA	ENST00000369850.10	c.6503-2A>C		splice_acceptor_variant, intron_variant		1	NM_001110556.2	ENSP00000358866.3

Frequencies

GnomAD3 genomes Cov.: 25

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 25

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Melnick-Needles syndrome;C0265293:Frontometaphyseal dysplasia;C1844696:Oto-palato-digital syndrome, type II;C1848213:Heterotopia, periventricular, X-linked dominant Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jun 21, 2016

In summary, donor and acceptor splice site variants are typically truncating (PMID: 16199547), and truncating variants in FLNA are known to be pathogenic (PMID: 26471271). However, without additional functional and/or genetic data, this variant has been classified as Likely Pathogenic. Algorithms developed to predict the effect of sequence changes on mRNA splicing suggest that this variant may alter mRNA splicing, but this prediction has not been confirmed by published transcriptional studies. This sequence change affects an acceptor splice site in intron 39 of the FLNA gene. It is expected to disrupt mRNA splicing and likely results in an absent or disrupted protein product. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a FLNA-related disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.74	D
BayesDel_noAF	Uncertain	-0.070
CADD	Pathogenic	33
DANN	Uncertain	0.99
FATHMM_MKL	Uncertain	0.97	D
GERP RS		5.2

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.95
SpliceAI score (max)		0.98		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.88		Position offset: -9
DS_AL_spliceai		0.98		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: rs112363874; hg19: chrX-153580817;