Genetic Variant NM_017565.4:c.590-2A>G (chr17-68554829-T-C) – ACMG Classification: Uncertain_significance (5 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PVS1_ModeratePM2PP5

The NM_017565.4(FAM20A):c.590-2A>G variant causes a splice acceptor, intron change. The variant allele was found at a frequency of 0.00000752 in 1,461,824 control chromosomes in the GnomAD database, with no homozygous occurrence. 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 Pathogenic (no stars).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000075 ( 0 hom. )

Consequence

FAM20A
NM_017565.4 splice_acceptor, intron

Scores

Splicing: ADA: 1.000

Clinical Significance

Pathogenic no assertion criteria provided P:1

Conservation

PhyloP100: 5.32

Variant links:

Genes affected

FAM20A (HGNC:23015): (FAM20A golgi associated secretory pathway pseudokinase) This locus encodes a protein that is likely secreted and may function in hematopoiesis. A mutation at this locus has been associated with amelogenesis imperfecta and gingival hyperplasia syndrome. Alternatively spliced transcript variants have been identified. [provided by RefSeq, Aug 2011]

FAM20A links:

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 5 ACMG points.

PVS1

Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.031365313 fraction of the gene. Cryptic splice site detected, with MaxEntScore 4, offset of 7, new splice context is: tcctcctttgcggattacAGtca. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 17-68554829-T-C is Pathogenic according to our data. Variant chr17-68554829-T-C is described in ClinVar as [Pathogenic]. Clinvar id is 35478.Status of the report is no_assertion_criteria_provided, 0 stars. Variant chr17-68554829-T-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FAM20A	NM_017565.4 link	c.590-2A>G		splice_acceptor_variant, intron_variant	Intron 2 of 10	ENST00000592554.2	NP_060035.2	Q96MK3L8B8N7Q8IYA5

Ensembl

Gene	Transcript	HGVSc	Effect	Exon rank	TSL	MANE	Protein	UniProt
FAM20A	ENST00000592554.2 link	c.590-2A>G	splice_acceptor_variant, intron_variant	Intron 2 of 10	1	NM_017565.4	ENSP00000468308.1	Q96MK3
FAM20A	ENST00000226094.9 link	n.247-2A>G	splice_acceptor_variant, intron_variant	Intron 2 of 10	1
FAM20A	ENST00000590074.5 link	n.*363-2A>G	splice_acceptor_variant, intron_variant	Intron 3 of 11	2		ENSP00000464910.1	K7EIV7
FAM20A	ENST00000592847.1 link	n.232-2A>G	splice_acceptor_variant, intron_variant	Intron 2 of 7	3

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

0.00000752

AC:

AN:

1461824

Hom.:

Cov.:

AF XY:

0.00000963

AC XY:

AN XY:

727216

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.000151

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000450

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

Alfa

AF:

0.0000329

Hom.:

Bravo

AF:

0.00000378

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

LINK: link

Submissions by phenotype

Amelogenesis imperfecta type 1G

Pathogenic:1

Jan 01, 2012

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

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Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.63

BayesDel_noAF

Uncertain

0.13

CADD

Pathogenic

DANN

Uncertain

0.99

Eigen

Pathogenic

1.0

Eigen_PC

Pathogenic

0.89

FATHMM_MKL

Uncertain

0.96

GERP RS

5.9

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.93

SpliceAI score (max)

0.99

Details are displayed if max score is > 0.2

DS_AL_spliceai

0.99

Position offset: -2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over