rs1554448978

Variant names:

• chr8-1771160-T-A
• rs1554448978
• NM_018941.4:c.106T>A

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 4P and 2B. PM1 PM2 BP4_Moderate

The NM_018941.4(CLN8):​c.106T>A​(p.Leu36Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000658 in 152,068 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/22 in silico tools predict a benign outcome for this variant. 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. L36F) has been classified as Uncertain significance.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: CLN8 NM_018941.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.149
• Publications: 0 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: Uncertain_significance. The variant received 2 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 16 uncertain in NM_018941.4
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.17546734).

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.106T>A	p.Leu36Met	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.106T>A	p.Leu36Met	missense	Exon 2 of 3	ENSP00000328182.4	Q9UBY8
	KBTBD11-OT1	ENST00000635855.1	TSL:5	n.106T>A		non_coding_transcript_exon	Exon 2 of 30	ENSP00000489726.1	A0A1B0GTJ5
	CLN8	ENST00000519254.2	TSL:5	c.106T>A	p.Leu36Met	missense	Exon 2 of 3	ENSP00000490016.1	Q9UBY8

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 152068 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000655

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

GnomAD4 exome Cov.: 32

GnomAD4 genome AF: 0.00000658 AC: 1 AN: 152068 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74282

African (AFR) AF: 0.00 AC: 0 AN: 41404

American (AMR) AF: 0.0000655 AC: 1 AN: 15274

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5150

South Asian (SAS) AF: 0.00 AC: 0 AN: 4822

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10606

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68020

Other (OTH) AF: 0.00 AC: 0 AN: 2092

Alfa AF: 0.00 Hom.: 0

ClinVar

ClinVar submissions

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	0.15
BayesDel_addAF	Benign	0.0095	T
BayesDel_noAF	Benign	-0.22
CADD	Benign	18
DANN	Uncertain	0.98
DEOGEN2	Benign	0.16	T
Eigen	Benign	-0.51
Eigen_PC	Benign	-0.49
FATHMM_MKL	Benign	0.61	D
LIST_S2	Benign	0.73	T
M_CAP	Uncertain	0.16	D
MetaRNN	Benign	0.18	T
MetaSVM	Benign	-0.31	T
MutationAssessor	Uncertain	2.5	M
PhyloP100		0.15
PrimateAI	Benign	0.43	T
PROVEAN	Benign	0.090	N
REVEL	Benign	0.23
Sift	Benign	0.082	T
Sift4G	Benign	0.14	T
Polyphen		0.52	P
Vest4		0.27
MutPred		0.35		Loss of catalytic residue at L36 (P = 0.1884)
MVP		0.79
MPC		0.046
ClinPred		0.20	T
GERP RS		0.042
Varity_R		0.056
gMVP		0.53
Mutation Taster		=92/8	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: rs1554448978; hg19: chr8-1719326;