rs1557191567

Positions:

• chrX-54495155-T-TA

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_004463.3(FGD1):​c.277_278insT​(p.Tyr93LeufsTer21) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 23)
• Consequence: FGD1 NM_004463.3 frameshift
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 1.75

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 Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant X-54495155-T-TA is Pathogenic according to our data. Variant chrX-54495155-T-TA is described in ClinVar as [Likely_pathogenic]. Clinvar id is 547364.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
FGD1	NM_004463.3	c.277_278insT	p.Tyr93LeufsTer21	frameshift_variant	1/18	ENST00000375135.4	NP_004454.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
FGD1	ENST00000375135.4	c.277_278insT	p.Tyr93LeufsTer21	frameshift_variant	1/18	1	NM_004463.3	ENSP00000364277	P1

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 23

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Aarskog syndrome Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	New York Genome Center	Jun 16, 2022	The de novo hemizygous one nucleotide duplication [c.277dup, p.(Tyr93LeufsTer21)] identified in exon 1 (of 18) of FGD1 has not been reported in affected individuals in the literature, though it has been deposited in the ClinVar database as Likely Pathogenic by another genetic testing laboratory [Variation ID: 547364]. This c.277dup alters the wild-type translational reading frame and is predicted to cause loss of normal protein function either through protein truncation or nonsense-mediated mRNA decay. This variant is absent from population databases (gnomADv2, gnomADv3, TOPMed Freeze 8) suggesting it is not a common benign variant in populations represented in those databases. Based on the available evidence, the de novo hemizygous one nucleotide duplication [c.277dup, p.(Tyr93LeufsTer21)] identified in the FGD1 gene is reported as Pathogenic. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Center for Human Genetics, Inc, Center for Human Genetics, Inc	Nov 01, 2016	- -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs1557191567; hg19: chrX-54521588;