15-68211862-A-G

Variant names:

• chr15-68211862-A-G
• rs1555438702
• NM_017882.3:c.299T>C

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1 PM2 PP3_Moderate

The NM_017882.3(CLN6):​c.299T>C​(p.Leu100Pro) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,154 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L100R) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: CLN6 NM_017882.3 missense, splice_region
• Scores: Splicing: ADA: 0.3436
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 8.88
• Publications: 0 publications found

Genes affected

CLN6 (HGNC:2077): (CLN6 transmembrane ER protein) This gene is one of eight which have been associated with neuronal ceroid lipofuscinoses (NCL). Also referred to as Batten disease, NCL comprises a class of autosomal recessive, neurodegenerative disorders affecting children. The genes responsible likely encode proteins involved in the degradation of post-translationally modified proteins in lysosomes. The primary defect in NCL disorders is thought to be associated with lysosomal storage function. [provided by RefSeq, Oct 2008]

CLN6 Gene-Disease associations (from GenCC):

• ceroid lipofuscinosis, neuronal, 6A

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Laboratory for Molecular Medicine, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), G2P, Myriad Women’s Health, Orphanet
• ceroid lipofuscinosis, neuronal, 6B (Kufs type)

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, G2P, Orphanet
• neuronal ceroid lipofuscinosis

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen

ENSG00000260007 (HGNC:):

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PM1: In a hotspot region, there are 7 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 13 uncertain in NM_017882.3
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.928

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CLN6	NM_017882.3	c.299T>C	p.Leu100Pro	missense_variant, splice_region_variant	Exon 4 of 7	ENST00000249806.11	NP_060352.1
CLN6	NM_001411068.1	c.395T>C	p.Leu132Pro	missense_variant, splice_region_variant	Exon 4 of 7		NP_001397997.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CLN6	ENST00000249806.11	c.299T>C	p.Leu100Pro	missense_variant, splice_region_variant	Exon 4 of 7	1	NM_017882.3	ENSP00000249806.5
ENSG00000260007	ENST00000562767.2	c.84-14234T>C		intron_variant	Intron 1 of 2	3		ENSP00000456336.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461154 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 726822

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

African (AFR) AF: 0.00 AC: 0 AN: 33476

American (AMR) AF: 0.00 AC: 0 AN: 44718

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26130

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

South Asian (SAS) AF: 0.00 AC: 0 AN: 86250

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52958

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5628

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111936

Other (OTH) AF: 0.00 AC: 0 AN: 60358

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.54	D
BayesDel_noAF	Pathogenic	0.53
CADD	Pathogenic	31
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.96	D;.;T;.
Eigen	Uncertain	0.67
Eigen_PC	Uncertain	0.65
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.90	D;D;T;D
M_CAP	Pathogenic	0.82	D
MetaRNN	Pathogenic	0.93	D;D;D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Uncertain	2.1	M;.;.;.
PhyloP100		8.9
PrimateAI	Uncertain	0.75	T
PROVEAN	Pathogenic	-5.2	D;D;.;D
REVEL	Pathogenic	0.95
Sift	Uncertain	0.0010	D;D;.;D
Sift4G	Uncertain	0.0020	D;D;.;D
Polyphen		1.0	D;.;.;.
Vest4		0.98
MutPred		0.65		.;Gain of loop (P = 0.0051);.;.;
MVP		0.99
MPC		1.3
ClinPred		1.0	D
GERP RS		5.1
Varity_R		0.95
gMVP		0.98
Mutation Taster		=15/85	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.34
dbscSNV1_RF	Benign	0.39
SpliceAI score (max)		0.020		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: rs1555438702; hg19: chr15-68504200;