chr7-258645-G-C

Variant names:

• chr7-258645-G-C
• NM_020223.4:c.1446-1G>C

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PVS1_Moderate PM2

The NM_020223.4(FAM20C):​c.1446-1G>C variant causes a splice acceptor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000722 in 1,384,546 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. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 7.2e-7 (0 hom.)
• Consequence: FAM20C NM_020223.4 splice_acceptor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.09

Genes affected

FAM20C (HGNC:22140): (FAM20C golgi associated secretory pathway kinase) This gene encodes a member of the family of secreted protein kinases. The encoded protein binds calcium and phosphorylates proteins involved in bone mineralization. Mutations in this gene are associated with the autosomal recessive disorder Raine syndrome. [provided by RefSeq, Apr 2014]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.034188036 fraction of the gene. Cryptic splice site detected, with MaxEntScore 3.7, offset of 49, new splice context is: ccatcctggtgccgctacAGcag. 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

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FAM20C	NM_020223.4	c.1446-1G>C		splice_acceptor_variant, intron_variant	Intron 8 of 9	ENST00000313766.6	NP_064608.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FAM20C	ENST00000313766.6	c.1446-1G>C		splice_acceptor_variant, intron_variant	Intron 8 of 9	1	NM_020223.4	ENSP00000322323.5
FAM20C	ENST00000515795.1	n.1103-1G>C		splice_acceptor_variant, intron_variant	Intron 5 of 6	1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 7.22e-7 AC: 1 AN: 1384546 Hom.: 0 Cov.: 31 AF XY: 0.00000146 AC XY: 1 AN XY: 683222

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 9.27e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.22
CADD	Pathogenic	32
DANN	Uncertain	0.99
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.82
FATHMM_MKL	Pathogenic	0.99	D
GERP RS		4.5

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.95
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.43		Position offset: 11
DS_AL_spliceai		0.99		Position offset: 1

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr7-298611;