17-68555742-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

4
2
1
Splicing: ADA: 0.9836
2

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]

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 Protein UniProt
FAM20ANM_017565.4 linkuse as main transcriptc.406C>T p.Arg136Ter stop_gained, splice_region_variant 2/11 ENST00000592554.2 NP_060035.2

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
FAM20AENST00000592554.2 linkuse as main transcriptc.406C>T p.Arg136Ter stop_gained, splice_region_variant 2/111 NM_017565.4 ENSP00000468308 P1
FAM20AENST00000226094.9 linkuse as main transcriptn.63C>T splice_region_variant, non_coding_transcript_exon_variant 2/111
FAM20AENST00000592847.1 linkuse as main transcriptn.48C>T splice_region_variant, non_coding_transcript_exon_variant 2/83
FAM20AENST00000590074.5 linkuse as main transcriptc.*179C>T splice_region_variant, 3_prime_UTR_variant, NMD_transcript_variant 3/122 ENSP00000464910

Frequencies

GnomAD3 genomes
AF:
0.0000920
AC:
14
AN:
152108
Hom.:
0
Cov.:
32
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:
11
AN:
251298
Hom.:
0
AF XY:
0.0000515
AC XY:
7
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:
82
AN:
1461742
Hom.:
0
Cov.:
32
AF XY:
0.0000550
AC XY:
40
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:
15
AN:
152226
Hom.:
0
Cov.:
32
AF XY:
0.000134
AC XY:
10
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.:
0
Bravo
AF:
0.000102
ESP6500AA
AF:
0.000454
AC:
2
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.0000412
AC:
5

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 submitterclinical testingGeneDxSep 27, 2022Nonsense 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) -
Pathogenic, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpMay 11, 2023This 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). -
Amelogenesis imperfecta type 1G Pathogenic:2
Pathogenic, criteria provided, single submitterclinical testingFulgent Genetics, Fulgent GeneticsFeb 09, 2022- -
Pathogenic, no assertion criteria providedliterature onlyOMIMJan 01, 2012- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.40
D
BayesDel_noAF
Pathogenic
0.60
CADD
Pathogenic
39
DANN
Uncertain
1.0
Eigen
Pathogenic
0.86
Eigen_PC
Pathogenic
0.74
FATHMM_MKL
Uncertain
0.88
D
MutationTaster
Benign
1.0
A
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.

Other links and lift over

dbSNP: rs144411158; hg19: chr17-66551883; COSMIC: COSV56837606; COSMIC: COSV56837606; API