X-154352449-T-G

Variant names:

• chrX-154352449-T-G
• rs112363874
• NM_001110556.2:c.6503-2A>C

Variant summary

Our verdict is Likely pathogenic. The variant received 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
• Publications: 0 publications found

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 Gene-Disease associations (from GenCC):

• periventricular nodular heterotopia

  Inheritance: AD, XL Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
• frontometaphyseal dysplasia 1

  Inheritance: XL Classification: DEFINITIVE Submitted by: G2P
• genetic developmental and epileptic encephalopathy

  Inheritance: XL Classification: DEFINITIVE Submitted by: G2P
• heterotopia, periventricular, X-linked dominant

  Inheritance: XL Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, G2P, Labcorp Genetics (formerly Invitae), Illumina
• intestinal pseudoobstruction, neuronal, chronic idiopathic, X-linked

  Inheritance: XL Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae)
• Melnick-Needles syndrome

  Inheritance: XL Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Orphanet, Labcorp Genetics (formerly Invitae)
• otopalatodigital syndrome type 2

  Inheritance: XL Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet, G2P, Labcorp Genetics (formerly Invitae)
• terminal osseous dysplasia-pigmentary defects syndrome

  Inheritance: XL Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Orphanet, Labcorp Genetics (formerly Invitae)
• cardiac valvular dysplasia, X-linked

  Inheritance: XL Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: Orphanet, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• frontometaphyseal dysplasia

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• congenital short bowel syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• otopalatodigital syndrome type 1

  Inheritance: XL Classification: SUPPORTIVE Submitted by: Orphanet
• X-linked Ehlers-Danlos syndrome

  Inheritance: XL Classification: SUPPORTIVE Submitted by: Orphanet
• familial thoracic aortic aneurysm and aortic dissection

  Inheritance: XL Classification: LIMITED Submitted by: ClinGen

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.033610273 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 VariationId is 405448.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FLNA	NM_001110556.2	c.6503-2A>C		splice_acceptor_variant, intron_variant	Intron 40 of 47	ENST00000369850.10	NP_001104026.1
FLNA	NM_001456.4	c.6479-2A>C		splice_acceptor_variant, intron_variant	Intron 39 of 46		NP_001447.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FLNA	ENST00000369850.10	c.6503-2A>C		splice_acceptor_variant, intron_variant	Intron 40 of 47	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

Jun 21, 2016

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. 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. 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. 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
PhyloP100		7.9
GERP RS		5.2
Mutation Taster		=0/100	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs112363874; hg19: chrX-153580817;