13-76995113-C-T

Variant names:

• chr13-76995113-C-T
• rs376336781
• NM_006493.4:c.224C>T

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM1 PM2 PP3

The NM_006493.4(CLN5):​c.224C>T​(p.Thr75Ile) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,794 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 Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T75S) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: CLN5 NM_006493.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.89
• Publications: 1 publications found

Genes affected

CLN5 (HGNC:2076): (CLN5 intracellular trafficking 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]

ENSG00000283208 (HGNC:):

FBXL3 (HGNC:13599): (F-box and leucine rich repeat protein 3) This gene encodes a member of the F-box protein family which is characterized by an approximately 40 amino acid motif, the F-box. The F-box proteins constitute one of the four subunits of ubiquitin protein ligase complex called SCFs (SKP1-cullin-F-box), which function in phosphorylation-dependent ubiquitination. The F-box proteins are divided into 3 classes: Fbws containing WD-40 domains, Fbls containing leucine-rich repeats, and Fbxs containing either different protein-protein interaction modules or no recognizable motifs. The protein encoded by this gene belongs to the Fbls class and, in addition to an F-box, contains several tandem leucine-rich repeats and is localized in the nucleus. [provided by RefSeq, Jul 2008]

FBXL3 Gene-Disease associations (from GenCC):

• intellectual disability, short stature, facial anomalies, and joint dislocations

  Inheritance: AR Classification: LIMITED Submitted by: Ambry Genetics

ACMG classification

Our verdict: Uncertain_significance. The variant received 5 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, 9 uncertain in NM_006493.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.771

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CLN5	NM_006493.4	c.224C>T	p.Thr75Ile	missense_variant	Exon 2 of 4	ENST00000377453.9	NP_006484.2
CLN5	NM_001366624.2	c.224C>T	p.Thr75Ile	missense_variant	Exon 2 of 5		NP_001353553.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CLN5	ENST00000377453.9	c.224C>T	p.Thr75Ile	missense_variant	Exon 2 of 4	1	NM_006493.4	ENSP00000366673.5
ENSG00000283208	ENST00000638147.2	c.224C>T	p.Thr75Ile	missense_variant	Exon 2 of 5	5		ENSP00000490953.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461794 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727192

African (AFR) AF: 0.0000299 AC: 1 AN: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44716

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26132

East Asian (EAS) AF: 0.00 AC: 0 AN: 39680

South Asian (SAS) AF: 0.00 AC: 0 AN: 86246

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

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

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1111964

Other (OTH) AF: 0.00 AC: 0 AN: 60390

GnomAD4 genome Cov.: 33

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000116 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Neuronal ceroid lipofuscinosis Uncertain:1

Feb 24, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces threonine, which is neutral and polar, with isoleucine, which is neutral and non-polar, at codon 124 of the CLN5 protein (p.Thr124Ile). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with CLN5-related conditions. ClinVar contains an entry for this variant (Variation ID: 527753). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.30
BayesDel_addAF	Pathogenic	0.23	D
BayesDel_noAF	Uncertain	0.10
CADD	Uncertain	23
DANN	Pathogenic	1.0
DEOGEN2	Benign	0.18	T;T;D;T;T;.
Eigen	Pathogenic	0.81
Eigen_PC	Pathogenic	0.80
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.88	D;.;D;.;.;.
M_CAP	Uncertain	0.10	D
MetaRNN	Pathogenic	0.77	D;D;D;D;D;D
MetaSVM	Uncertain	0.68	D
MutationAssessor	Uncertain	2.1	.;.;M;.;.;.
PhyloP100		7.9
PrimateAI	Uncertain	0.62	T
REVEL	Uncertain	0.61
Polyphen		1.0	.;.;D;.;.;.
MVP		0.99
MPC		0.61
ClinPred		0.88	D
GERP RS		5.8
Varity_R		0.22
Mutation Taster		=62/38	polymorphism

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: rs376336781; hg19: chr13-77569248;