17-68555742-G-A

Position:

chr17-68555742-G-A

Variant summary

Our verdict is Pathogenic. Variant got 19 ACMG points: 19P and 0B. PVS1PM2PP3PP5_Very_Strong

The NM_017565.4(FAM20A):c.406C>T(p.Arg136Ter) variant causes a stop gained, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000601 in 1,613,968 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000099 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000056 ( 0 hom. )

Consequence

FAM20A
NM_017565.4 stop_gained, splice_region

Scores

Splicing: ADA: 0.9836

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:4

Conservation

PhyloP100: 2.08

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:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 19 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;

PP3

Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.

PP5

Variant 17-68555742-G-A is Pathogenic according to our data. Variant chr17-68555742-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 30879.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr17-68555742-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
FAM20A	NM_017565.4 linkuse as main transcript	c.406C>T	p.Arg136Ter	stop_gained, splice_region_variant	2/11	ENST00000592554.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris
FAM20A	ENST00000592554.2 linkuse as main transcript	c.406C>T	p.Arg136Ter	stop_gained, splice_region_variant	2/11	1	NM_017565.4	P1
FAM20A	ENST00000226094.9 linkuse as main transcript	n.63C>T		splice_region_variant, non_coding_transcript_exon_variant	2/11	1
FAM20A	ENST00000592847.1 linkuse as main transcript	n.48C>T		splice_region_variant, non_coding_transcript_exon_variant	2/8	3
FAM20A	ENST00000590074.5 linkuse as main transcript	c.*179C>T		splice_region_variant, 3_prime_UTR_variant, NMD_transcript_variant	3/12	2

Frequencies

GnomAD3 genomes

AF:

0.0000920

AC:

AN:

152108

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000266

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000208

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000438

AC:

AN:

251298

Hom.:

AF XY:

0.0000515

AC XY:

AN XY:

135852

show subpopulations

Gnomad AFR exome

AF:

0.000431

Gnomad AMR exome

AF:

0.0000578

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.0000561

AC:

AN:

1461742

Hom.:

Cov.:

AF XY:

0.0000550

AC XY:

AN XY:

727164

show subpopulations

Gnomad4 AFR exome

AF:

0.000568

Gnomad4 AMR exome

AF:

0.0000671

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000580

Gnomad4 FIN exome

AF:

0.0000187

Gnomad4 NFE exome

AF:

0.0000432

Gnomad4 OTH exome

AF:

0.0000994

GnomAD4 genome

AF:

0.0000985

AC:

AN:

152226

Hom.:

Cov.:

AF XY:

0.000134

AC XY:

AN XY:

74410

show subpopulations

Gnomad4 AFR

AF:

0.000289

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.000208

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000294

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000321

Hom.:

Bravo

AF:

0.000102

ESP6500AA

AF:

0.000454

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000412

AC:

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Invitae	May 11, 2023	This premature translational stop signal has been observed in individual(s) with amelogenesis imperfecta and/or enamel-renal syndrome (PMID: 21549343, 23434854, 28086997). For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 30879). This variant is present in population databases (rs144411158, gnomAD 0.04%). This sequence change creates a premature translational stop signal (p.Arg136*) in the FAM20A gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in FAM20A are known to be pathogenic (PMID: 21990045, 23434854). -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Sep 27, 2022	Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss of function is a known mechanism of disease; This variant is associated with the following publications: (PMID: 28086997, 18597613, 28694781, 23468644, 21549343, 23434854) -

Amelogenesis imperfecta type 1G

Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Fulgent Genetics, Fulgent Genetics	Feb 09, 2022	- -
Pathogenic, no assertion criteria provided	literature only	OMIM	Jan 01, 2012	- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.40

BayesDel_noAF

Pathogenic

0.60

CADD

Pathogenic

DANN

Uncertain

1.0

Eigen

Pathogenic

0.86

Eigen_PC

Pathogenic

0.74

FATHMM_MKL

Uncertain

0.88

MutationTaster

Benign

1.0

Vest4

0.32

GERP RS

5.8

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

0.98

dbscSNV1_RF

Pathogenic

0.84

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

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