chr16-28489290-A-G

Position:

• chr16-28489290-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 3P and 1B. PM2 PP3 BP7

The NM_001042432.2(CLN3):​c.222T>C​(p.His74=) variant causes a splice region, synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000101 in 1,607,466 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. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.000046 (0 hom., cov: 32)
  • Exomes 𝑓: 0.00011 (0 hom.)
• Consequence: CLN3 NM_001042432.2 splice_region, synonymous
• Scores: Splicing: ADA: 0.0002566
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4 B:4
• Conservation: PhyloP100: -0.682

Genes affected

CLN3 (HGNC:2074): (CLN3 lysosomal/endosomal transmembrane protein, battenin) This gene encodes a protein that is involved in lysosomal function. Mutations in this, as well as other neuronal ceroid-lipofuscinosis (CLN) genes, cause neurodegenerative diseases commonly known as Batten disease or collectively known as neuronal ceroid lipofuscinoses (NCLs). Many alternatively spliced transcript variants have been found for this gene. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: BayesDel_noAF computational evidence supports a deleterious effect, 0.15
• BP7: Synonymous conserved (PhyloP=-0.682 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CLN3	NM_001042432.2	c.222T>C	p.His74=	splice_region_variant, synonymous_variant	4/16	ENST00000636147.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CLN3	ENST00000636147.2	c.222T>C	p.His74=	splice_region_variant, synonymous_variant	4/16	1	NM_001042432.2	P1

Frequencies

GnomAD3 genomes AF: 0.0000460 AC: 7 AN: 152086 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

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: 0.000103

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000685 AC: 17 AN: 248016 Hom.: 0 AF XY: 0.0000597 AC XY: 8 AN XY: 134078

Gnomad AFR exome AF: 0.0000630

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.000235

Gnomad NFE exome AF: 0.0000891

Gnomad OTH exome AF: 0.000165

GnomAD4 exome AF: 0.000107 AC: 155 AN: 1455380 Hom.: 0 Cov.: 30 AF XY: 0.000102 AC XY: 74 AN XY: 724126

Gnomad4 AFR exome AF: 0.0000899

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.000413

Gnomad4 NFE exome AF: 0.000108

Gnomad4 OTH exome AF: 0.000166

GnomAD4 genome AF: 0.0000460 AC: 7 AN: 152086 Hom.: 0 Cov.: 32 AF XY: 0.0000404 AC XY: 3 AN XY: 74302

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.000103

Gnomad4 OTH AF: 0.00

Alfa AF: 0.000109 Hom.: 1

Bravo AF: 0.0000529

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:4 Benign:4

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Benign:3

Likely benign, no assertion criteria provided	clinical testing	Genome Diagnostics Laboratory, Amsterdam University Medical Center	-	- -
Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Nov 21, 2018	- -
Likely benign, no assertion criteria provided	clinical testing	Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center	-	- -

Neuronal ceroid lipofuscinosis Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Aug 05, 2022	This sequence change affects codon 74 of the CLN3 mRNA. It is a 'silent' change, meaning that it does not change the encoded amino acid sequence of the CLN3 protein. It affects a nucleotide within the consensus splice site. This variant is present in population databases (rs201225986, gnomAD 0.02%). This variant has not been reported in the literature in individuals affected with CLN3-related conditions. ClinVar contains an entry for this variant (Variation ID: 457951). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant is not likely to affect RNA splicing. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -
Uncertain significance, no assertion criteria provided	clinical testing	Natera, Inc.	Apr 24, 2020	- -

Neuronal ceroid lipofuscinosis 3 Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Jan 12, 2018	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, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -
Uncertain significance, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Aug 10, 2021	- -

not specified Benign:1

Benign, no assertion criteria provided

clinical testing

Genome Diagnostics Laboratory, University Medical Center Utrecht

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Pathogenic	0.15
CADD	Benign	0.58
DANN	Benign	0.72

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.00026
dbscSNV1_RF	Benign	0.090
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

Publications

LitVar

Other links and lift over

dbSNP: rs201225986; hg19: chr16-28500611;