X-154365437-C-G

Position:

• chrX-154365437-C-G

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 3P and 1B. PM2 PP2 BP4

The NM_001110556.2(FLNA):​c.1479G>C​(p.Lys493Asn) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. K493R) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 24)
• Consequence: FLNA NM_001110556.2 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2 B:1
• Conservation: PhyloP100: -0.0900

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), FLNA. . Gene score misZ 3.7802 (greater than the threshold 3.09). GenCC has associacion of gene with X-linked Ehlers-Danlos syndrome, terminal osseous dysplasia-pigmentary defects syndrome, FG syndrome 2, frontometaphyseal dysplasia, heterotopia, periventricular, X-linked dominant, Melnick-Needles syndrome, otopalatodigital syndrome type 2, periventricular nodular heterotopia, otopalatodigital syndrome type 1, intestinal pseudoobstruction, neuronal, chronic idiopathic, X-linked, familial thoracic aortic aneurysm and aortic dissection, congenital short bowel syndrome, frontometaphyseal dysplasia 1, cardiac valvular dysplasia, X-linked.
• BP4: Computational evidence support a benign effect (MetaRNN=0.37430683).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
FLNA	NM_001110556.2	c.1479G>C	p.Lys493Asn	missense_variant	10/48	ENST00000369850.10
FLNA	NM_001456.4	c.1479G>C	p.Lys493Asn	missense_variant	10/47

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
FLNA	ENST00000369850.10	c.1479G>C	p.Lys493Asn	missense_variant	10/48	1	NM_001110556.2

Frequencies

GnomAD3 genomes Cov.: 24

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 24

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2 Benign:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

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

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Sep 27, 2022

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt FLNA protein function. ClinVar contains an entry for this variant (Variation ID: 464974). This variant has not been reported in the literature in individuals affected with FLNA-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces lysine, which is basic and polar, with asparagine, which is neutral and polar, at codon 493 of the FLNA protein (p.Lys493Asn). -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Nov 11, 2021

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

FG syndrome 2 Benign:1

Likely benign, no assertion criteria provided

clinical testing

Service de Génétique Moléculaire, Hôpital Robert Debré

-

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.89
BayesDel_addAF	Benign	-0.15	T
BayesDel_noAF	Benign	-0.45
CADD	Benign	19
DANN	Benign	0.88
DEOGEN2	Uncertain	0.61	D;.;.;.;.
FATHMM_MKL	Benign	0.67	D
LIST_S2	Uncertain	0.97	D;D;.;D;D
M_CAP	Uncertain	0.094	D
MetaRNN	Benign	0.37	T;T;T;T;T
MetaSVM	Benign	-0.41	T
MutationAssessor	Benign	1.9	L;.;L;L;.
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Uncertain	0.72	T
PROVEAN	Uncertain	-3.5	D;.;D;D;.
REVEL	Uncertain	0.34
Sift	Benign	0.094	T;.;T;T;.
Sift4G	Benign	0.17	T;T;T;T;T
Polyphen		0.24	B;.;B;B;.
Vest4		0.52
MutPred		0.39		Loss of glycosylation at K493 (P = 0.0331);.;Loss of glycosylation at K493 (P = 0.0331);Loss of glycosylation at K493 (P = 0.0331);.;
MVP		0.88
MPC		1.5
ClinPred		0.89	D
GERP RS		-1.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.8
Varity_R		0.66
gMVP		0.52

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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: rs1557179001; hg19: chrX-153593805;