chr8-1780472-C-G

Variant names:

• chr8-1780472-C-G
• rs386834138
• NM_018941.4:c.766C>G

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM1 PM2 PP3_Moderate PP5

The NM_018941.4(CLN8):​c.766C>G​(p.Gln256Glu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,892 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (no stars).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: CLN8 NM_018941.4 missense
• Clinical Significance: Likely pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 7.37
• Publications: 5 publications found

Genes affected

CLN8 (HGNC:2079): (CLN8 transmembrane ER and ERGIC protein) This gene encodes a transmembrane protein belonging to a family of proteins containing TLC domains, which are postulated to function in lipid synthesis, transport, or sensing. The protein localizes to the endoplasmic reticulum (ER), and may recycle between the ER and ER-Golgi intermediate compartment. Mutations in this gene are associated with a disorder characterized by progressive epilepsy with cognitive disabilities (EPMR), which is a subtype of neuronal ceroid lipofuscinoses (NCL). Patients with mutations in this gene have altered levels of sphingolipid and phospholipids in the brain. [provided by RefSeq, Jul 2017]

CLN8 Gene-Disease associations (from GenCC):

• neuronal ceroid lipofuscinosis

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• neuronal ceroid lipofuscinosis 8

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet, Myriad Women’s Health, Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
• neuronal ceroid lipofuscinosis 8 northern epilepsy variant

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet
• autism spectrum disorder

  Inheritance: AD Classification: NO_KNOWN Submitted by: Ambry Genetics

KBTBD11-OT1 (HGNC:):

ACMG classification

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 11 uncertain in NM_018941.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.936
• PP5: Variant 8-1780472-C-G is Pathogenic according to our data. Variant chr8-1780472-C-G is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 56719.Status of the report is no_assertion_criteria_provided, 0 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_018941.4. 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
	CLN8	NM_018941.4	MANE Select	c.766C>G	p.Gln256Glu	missense	Exon 3 of 3	NP_061764.2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CLN8	ENST00000331222.6	TSL:1 MANE Select	c.766C>G	p.Gln256Glu	missense	Exon 3 of 3	ENSP00000328182.4	Q9UBY8
	KBTBD11-OT1	ENST00000635855.1	TSL:5	n.543+8875C>G		intron	N/A	ENSP00000489726.1	A0A1B0GTJ5
	CLN8	ENST00000519254.2	TSL:5	c.766C>G	p.Gln256Glu	missense	Exon 3 of 3	ENSP00000490016.1	Q9UBY8

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461892 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727248

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: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

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

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1112012

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome Cov.: 33

ClinVar

ClinVar submissions

Significance: Likely pathogenic

Revision: no assertion criteria provided

Pathogenic	VUS	Benign	Condition
1	-	-	Neuronal ceroid lipofuscinosis 8 (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.65
BayesDel_addAF	Pathogenic	0.47	D
BayesDel_noAF	Pathogenic	0.44
CADD	Uncertain	25
DANN	Uncertain	0.99
DEOGEN2	Benign	0.32	T
Eigen	Pathogenic	0.72
Eigen_PC	Uncertain	0.66
FATHMM_MKL	Pathogenic	0.98	D
M_CAP	Uncertain	0.11	D
MetaRNN	Pathogenic	0.94	D
MetaSVM	Pathogenic	0.85	D
MutationAssessor	Uncertain	2.5	M
PhyloP100		7.4
PrimateAI	Uncertain	0.60	T
PROVEAN	Benign	-1.3	N
REVEL	Pathogenic	0.85
Sift	Pathogenic	0.0	D
Sift4G	Uncertain	0.026	D
Polyphen		1.0	D
Vest4		0.86
MutPred		0.82		Gain of loop (P = 0.0435)
MVP		0.97
MPC		0.28
ClinPred		0.97	D
GERP RS		5.2
Varity_R		0.52
gMVP		0.78
Mutation Taster		=30/70	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs386834138; hg19: chr8-1728638;