19-29702971-GCCC-GCCCC

Variant names:

• chr19-29702971-G-GC
• rs398122409
• NM_031448.6:c.166dupG

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PVS1 PM2 PP5

The NM_031448.6(C19orf12):​c.166dupG​(p.Ala56GlyfsTer16) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,794 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: C19orf12 NM_031448.6 frameshift
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:2
• Conservation: PhyloP100: 2.30
• Publications: 4 publications found

Genes affected

C19orf12 (HGNC:25443): (chromosome 19 open reading frame 12) This gene encodes a small transmembrane protein. Mutations in this gene are a cause of neurodegeneration with brain iron accumulation-4 (NBIA4), but the specific function of the encoded protein is unknown. Alternatively spliced transcript variants encoding multiple isoforms have been observed for this gene. [provided by RefSeq, Dec 2011]

C19orf12 Gene-Disease associations (from GenCC):

• neurodegeneration with brain iron accumulation 4

  Inheritance: AR, SD, AD Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, Genomics England PanelApp, Illumina, Ambry Genetics, G2P
• hereditary spastic paraplegia 43

  Inheritance: AR Classification: LIMITED Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Ambry Genetics

ACMG classification

Our verdict: Pathogenic. The variant received 11 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 24 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 19-29702971-G-GC is Pathogenic according to our data. Variant chr19-29702971-G-GC is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 1682831.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_031448.6. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	C19orf12	NM_031448.6	MANE Select	c.166dupG	p.Ala56GlyfsTer16	frameshift	Exon 3 of 3	NP_113636.2
	C19orf12	NM_001031726.4		c.166dupG	p.Ala56GlyfsTer16	frameshift	Exon 3 of 3	NP_001026896.3
	C19orf12	NM_001256047.2		c.166dupG	p.Ala56GlyfsTer16	frameshift	Exon 3 of 3	NP_001242976.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	C19orf12	ENST00000323670.14	TSL:2 MANE Select	c.166dupG	p.Ala56GlyfsTer16	frameshift	Exon 3 of 3	ENSP00000313332.9
	C19orf12	ENST00000592153.5	TSL:1	c.166dupG	p.Ala56GlyfsTer16	frameshift	Exon 3 of 4	ENSP00000467117.1
	C19orf12	ENST00000591243.1	TSL:1	c.166dupG	p.Ala56GlyfsTer16	frameshift	Exon 2 of 2	ENSP00000467516.1

Frequencies

GnomAD3 genomes AF: 0.00000659 AC: 1 AN: 151632 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000242

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000121 AC: 3 AN: 248898 AF XY: 0.00000742

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000180

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461794 Hom.: 0 Cov.: 37 AF XY: 0.00000138 AC XY: 1 AN XY: 727198

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53376

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111960

Other (OTH) AF: 0.0000166 AC: 1 AN: 60394

GnomAD4 genome Data not reliable, filtered out with message: AS_VQSR AF: 0.00000659 AC: 1 AN: 151632 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74036

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.0000242 AC: 1 AN: 41258

American (AMR) AF: 0.00 AC: 0 AN: 15212

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3468

East Asian (EAS) AF: 0.00 AC: 0 AN: 5158

South Asian (SAS) AF: 0.00 AC: 0 AN: 4810

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10530

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 314

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 67892

Other (OTH) AF: 0.00 AC: 0 AN: 2078

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

ClinVar submissions as Germline

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

Pathogenic	VUS	Benign	Condition
-	2	-	Hereditary spastic paraplegia 43 (2)
1	-	-	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		2.3
Mutation Taster		=2/198	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.080		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs398122409; hg19: chr19-30193878; COSMIC: COSV60365095;