Genetic Variant FGD4:p.Ala643Ala (chr12-32624428-G-T) – ACMG Classification: Likely_benign (-3 pts)

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2BP4_ModerateBP6_ModerateBP7

The NM_001370298.3(FGD4):c.1929G>T(p.Ala643Ala) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000251 in 1,596,664 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★). Synonymous variant affecting the same amino acid position (i.e. A643A) has been classified as Benign.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

FGD4
NM_001370298.3 synonymous

Scores

Clinical Significance

Likely benign criteria provided, single submitter B:1

Conservation

PhyloP100: 0.526

Publications

12 publications found

Variant links:

Genes affected

FGD4 (HGNC:19125): (FYVE, RhoGEF and PH domain containing 4) This gene encodes a protein that is involved in the regulation of the actin cytoskeleton and cell shape. This protein contains an actin filament-binding domain, which together with its Dbl homology domain and one of its pleckstrin homology domains, can form microspikes. This protein can activate MAPK8 independently of the actin filament-binding domain, and it is also involved in the activation of CDC42 via the exchange of bound GDP for free GTP. The activation of CDC42 also enables this protein to play a role in mediating the cellular invasion of Cryptosporidium parvum, an intracellular parasite that infects the gastrointestinal tract. Mutations in this gene can cause Charcot-Marie-Tooth disease type 4H (CMT4H), a disorder of the peripheral nervous system. Multiple alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jan 2015]

FGD4 Gene-Disease associations (from GenCC):

Charcot-Marie-Tooth disease
Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
Charcot-Marie-Tooth disease type 4H
Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet

FGD4 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -3 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.4).

BP6

Variant 12-32624428-G-T is Benign according to our data. Variant chr12-32624428-G-T is described in ClinVar as Likely_benign. ClinVar VariationId is 1643736.Status of the report is criteria_provided_single_submitter, 1 stars.

BP7

Synonymous conserved (PhyloP=0.526 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001370298.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
FGD4	NM_001370298.3	MANE Select	c.1929G>T	p.Ala643Ala	synonymous	Exon 12 of 17	NP_001357227.2
FGD4	NM_001384126.1		c.1929G>T	p.Ala643Ala	synonymous	Exon 12 of 18	NP_001371055.1
FGD4	NM_001304481.2		c.1773G>T	p.Ala591Ala	synonymous	Exon 12 of 17	NP_001291410.1

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
FGD4	ENST00000534526.7	TSL:5 MANE Select	c.1929G>T	p.Ala643Ala	synonymous	Exon 12 of 17	ENSP00000449273.1
FGD4	ENST00000395740.5	TSL:1	n.*910G>T		non_coding_transcript_exon	Exon 13 of 17	ENSP00000379089.1
FGD4	ENST00000395740.5	TSL:1	n.*910G>T		3_prime_UTR	Exon 13 of 17	ENSP00000379089.1

Frequencies

GnomAD3 genomes

AF:

0.00000660

AC:

AN:

151604

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.00000815

AC:

AN:

245294

AF XY:

0.00000754

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000588

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000208

AC:

AN:

1445060

Hom.:

Cov.:

AF XY:

0.00000139

AC XY:

AN XY:

719240

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33228

American (AMR)

AF:

0.0000451

AC:

AN:

44308

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

25818

East Asian (EAS)

AF:

0.00

AC:

AN:

39610

South Asian (SAS)

AF:

0.00

AC:

AN:

85370

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53142

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5110

European-Non Finnish (NFE)

AF:

9.10e-7

AC:

AN:

1098732

Other (OTH)

AF:

0.00

AC:

AN:

59742

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.425

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.00000660

AC:

AN:

151604

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

73988

show subpopulations

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR)

AF:

0.00

AC:

AN:

41240

American (AMR)

AF:

0.00

AC:

AN:

15210

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5170

South Asian (SAS)

AF:

0.00

AC:

AN:

4816

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10442

Middle Eastern (MID)

AF:

0.00

AC:

AN:

314

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

67958

Other (OTH)

AF:

0.00

AC:

AN:

2080

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.325

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.00

Hom.:

4874

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Charcot-Marie-Tooth disease type 4

Benign:1

May 24, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.40

CADD

Benign

3.0

(source)

DANN

Benign

0.56

PhyloP100

0.53

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over