9-27547022-A-G

Variant names:

• chr9-27547022-A-G
• rs191690136
• NM_018325.5:c.*1214T>C

Variant summary

Our verdict is Benign. The variant received -10 ACMG points: 0P and 10B. BP4_Strong BP6_Moderate BS2

The NM_018325.5(C9orf72):​c.*1214T>C variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00188 in 152,284 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★).

• Frequency: Genomes: 𝑓 0.0019 (2 hom., cov: 32)
• Consequence: C9orf72 NM_018325.5 3_prime_UTR
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: 0.156
• Publications: 0 publications found

Genes affected

C9orf72 (HGNC:28337): (C9orf72-SMCR8 complex subunit) The protein encoded by this gene plays an important role in the regulation of endosomal trafficking, and has been shown to interact with Rab proteins that are involved in autophagy and endocytic transport. Expansion of a GGGGCC repeat from 2-22 copies to 700-1600 copies in the intronic sequence between alternate 5' exons in transcripts from this gene is associated with 9p-linked ALS (amyotrophic lateral sclerosis) and FTD (frontotemporal dementia) (PMID: 21944778, 21944779). Studies suggest that hexanucleotide expansions could result in the selective stabilization of repeat-containing pre-mRNA, and the accumulation of insoluble dipeptide repeat protein aggregates that could be pathogenic in FTD-ALS patients (PMID: 23393093). Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Jul 2016]

C9orf72 Gene-Disease associations (from GenCC):

• frontotemporal dementia and/or amyotrophic lateral sclerosis 1

  Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE Submitted by: ClinGen, Labcorp Genetics (formerly Invitae), Ambry Genetics
• progressive myoclonus epilepsy

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics

ACMG classification

Our verdict: Benign. The variant received -10 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.84).
• BP6: Variant 9-27547022-A-G is Benign according to our data. Variant chr9-27547022-A-G is described in ClinVar as [Likely_benign]. Clinvar id is 912912.Status of the report is criteria_provided_single_submitter, 1 stars.
• BS2: High AC in GnomAd4 at 286 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
C9orf72	NM_018325.5	c.*1214T>C		3_prime_UTR_variant	Exon 11 of 11	ENST00000380003.8	NP_060795.1
C9orf72	NM_001256054.3	c.*1214T>C		3_prime_UTR_variant	Exon 11 of 11		NP_001242983.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
C9orf72	ENST00000380003.8	c.*1214T>C		3_prime_UTR_variant	Exon 11 of 11	1	NM_018325.5	ENSP00000369339.3

Frequencies

GnomAD3 genomes AF: 0.00188 AC: 286 AN: 152166 Hom.: 2 Cov.: 32

Gnomad AFR AF: 0.00664

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000196

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: 0.0000441

Gnomad OTH AF: 0.00240

GnomAD4 exome Cov.: 0

GnomAD4 genome AF: 0.00188 AC: 286 AN: 152284 Hom.: 2 Cov.: 32 AF XY: 0.00205 AC XY: 153 AN XY: 74464

African (AFR) AF: 0.00662 AC: 275 AN: 41568

American (AMR) AF: 0.000196 AC: 3 AN: 15294

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3466

East Asian (EAS) AF: 0.00 AC: 0 AN: 5194

South Asian (SAS) AF: 0.00 AC: 0 AN: 4824

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10616

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.0000441 AC: 3 AN: 68010

Other (OTH) AF: 0.00237 AC: 5 AN: 2106

Alfa AF: 0.000619 Hom.: 0

Bravo AF: 0.00199

Asia WGS AF: 0.000289 AC: 1 AN: 3478

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

Frontotemporal dementia and/or amyotrophic lateral sclerosis 1 Benign:1

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.84
CADD	Benign	1.5
DANN	Benign	0.67
PhyloP100		0.16
Mutation Taster		=100/0	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
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

Other links and lift over

dbSNP: rs191690136; hg19: chr9-27547020;