chr8-1771113-C-T

Variant names:

• chr8-1771113-C-T
• rs749651452
• NM_018941.4:c.59C>T

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM1

The NM_018941.4(CLN8):​c.59C>T​(p.Ser20Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000185 in 1,461,888 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S20T) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.000018 (0 hom.)
• Consequence: CLN8 NM_018941.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.67
• Publications: 2 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: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, G2P, Orphanet, Ambry Genetics, Myriad Women’s Health
• 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: Uncertain_significance. The variant received 2 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 18 uncertain in NM_018941.4

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.59C>T	p.Ser20Phe	missense	Exon 2 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.59C>T	p.Ser20Phe	missense	Exon 2 of 3	ENSP00000328182.4
	KBTBD11-OT1	ENST00000635855.1	TSL:5	n.59C>T		non_coding_transcript_exon	Exon 2 of 30	ENSP00000489726.1
	CLN8	ENST00000519254.2	TSL:5	c.59C>T	p.Ser20Phe	missense	Exon 2 of 3	ENSP00000490016.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.0000185 AC: 27 AN: 1461888 Hom.: 0 Cov.: 32 AF XY: 0.0000179 AC XY: 13 AN XY: 727244

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: 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: 0.0000225 AC: 25 AN: 1112008

Other (OTH) AF: 0.0000166 AC: 1 AN: 60396

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000151

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

ClinVar submissions as Germline

Significance: Uncertain significance

Revision: criteria provided, single submitter

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

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.27
BayesDel_addAF	Pathogenic	0.16	D
BayesDel_noAF	Uncertain	0.0
CADD	Benign	22
DANN	Uncertain	1.0
DEOGEN2	Benign	0.38	T
Eigen	Uncertain	0.20
Eigen_PC	Benign	0.093
FATHMM_MKL	Uncertain	0.88	D
LIST_S2	Uncertain	0.86	D
M_CAP	Pathogenic	0.31	D
MetaRNN	Uncertain	0.61	D
MetaSVM	Uncertain	0.60	D
MutationAssessor	Uncertain	2.5	M
PhyloP100		2.7
PrimateAI	Benign	0.44	T
PROVEAN	Benign	-1.5	N
REVEL	Uncertain	0.61
Sift	Benign	0.072	T
Sift4G	Uncertain	0.027	D
Polyphen		0.99	D
Vest4		0.49
MutPred		0.48		Loss of helix (P = 0.0558)
MVP		0.91
MPC		0.14
ClinPred		0.92	D
GERP RS		4.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.048
gMVP		0.74
Mutation Taster		=78/22	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: rs749651452; hg19: chr8-1719279;