rs1557188474

Variant names:

• chrX-54455485-C-T
• rs1557188474
• NM_004463.3:c.1978G>A

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2 PP2 PP3_Moderate

The NM_004463.3(FGD1):​c.1978G>A​(p.Val660Met) 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 pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 24)
• Consequence: FGD1 NM_004463.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.02

Genes affected

FGD1 (HGNC:3663): (FYVE, RhoGEF and PH domain containing 1) This gene encodes a protein that contains Dbl (DH) and pleckstrin (PH) homology domains and is similar to the Rho family of small GTP-binding proteins. The encoded protein specifically binds to the Rho family GTPase Cdc42Hs and can stimulate the GDP-GTP exchange of the isoprenylated form of Cdc42Hs. It also stimulates the mitogen activated protein kinase cascade leading to c-Jun kinase SAPK/JNK1 activation. Defects in this gene are the cause of the faciogenital dysplasia in Aarskog-Scott syndrome and a syndromatic form of X-linked cognitive disability. [provided by RefSeq, Jul 2017]

ACMG classification

Verdict is Uncertain_significance. Variant got 5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the FGD1 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 11 curated pathogenic missense variants (we use a threshold of 10). The gene has 24 curated benign missense variants. Gene score misZ: 3.5183 (above the threshold of 3.09). GenCC associations: The gene is linked to Aarskog-Scott syndrome, X-linked.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.846

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FGD1	NM_004463.3	c.1978G>A	p.Val660Met	missense_variant	Exon 12 of 18	ENST00000375135.4	NP_004454.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FGD1	ENST00000375135.4	c.1978G>A	p.Val660Met	missense_variant	Exon 12 of 18	1	NM_004463.3	ENSP00000364277.3

Frequencies

GnomAD3 genomes Cov.: 24

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 24

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Inborn genetic diseases Uncertain:1

Dec 17, 2015

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.97
BayesDel_addAF	Pathogenic	0.16	D
BayesDel_noAF	Uncertain	-0.010
CADD	Pathogenic	27
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.64	D
FATHMM_MKL	Uncertain	0.92	D
LIST_S2	Pathogenic	0.99	D
M_CAP	Pathogenic	0.63	D
MetaRNN	Pathogenic	0.85	D
MetaSVM	Pathogenic	0.84	D
MutationAssessor	Uncertain	2.5	M
PrimateAI	Pathogenic	0.80	D
PROVEAN	Uncertain	-2.4	N
REVEL	Uncertain	0.62
Sift	Uncertain	0.0010	D
Sift4G	Uncertain	0.0030	D
Polyphen		1.0	D
Vest4		0.55
MutPred		0.72		Gain of disorder (P = 0.0426);
MVP		0.94
MPC		2.4
ClinPred		0.98	D
GERP RS		5.0
Varity_R		0.70
gMVP		0.80

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		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: rs1557188474; hg19: chrX-54481918;