rs587776914

chr17-68554829-T-C

Variant summary

Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PVS1_Moderate PM2 PP3_Strong PP5

The NM_017565.4(FAM20A):c.590-2A>G variant causes a splice acceptor 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
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 5.32

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]

ACMG classification

Verdict is Likely_pathogenic. Variant got 9 ACMG points.

• PVS1: Splicing variant, NOT destroyed by nmd, known LOF gene, truncates exone, which is 0.030750308 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
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• 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/exons	MANE	UniProt
FAM20A	NM_017565.4	c.590-2A>G		splice_acceptor_variant		ENST00000592554.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
FAM20A	ENST00000592554.2	c.590-2A>G		splice_acceptor_variant		1	NM_017565.4	P1
FAM20A	ENST00000226094.9	n.247-2A>G		splice_acceptor_variant, non_coding_transcript_variant		1
FAM20A	ENST00000590074.5	c.*363-2A>G		splice_acceptor_variant, NMD_transcript_variant		2
FAM20A	ENST00000592847.1	n.232-2A>G		splice_acceptor_variant, non_coding_transcript_variant		3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000752 AC: 11 AN: 1461824 Hom.: 0 Cov.: 33 AF XY: 0.00000963 AC XY: 7 AN XY: 727216

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.: 32

Alfa AF: 0.0000329 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

Submissions by phenotype

Amelogenesis imperfecta type 1G Pathogenic:1

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	0.63	D
BayesDel_noAF	Uncertain	0.13
Cadd	Pathogenic	30
Dann	Uncertain	0.99
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.89
FATHMM_MKL	Uncertain	0.96	D
MutationTaster	Benign	1.0	D
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

Other links and lift over

dbSNP: rs587776914; hg19: chr17-66550970;