rs374146578

Variant names:

• chr11-6613006-A-G
• rs374146578
• NM_000391.4:c.*1540T>C

Variant summary

Our verdict is Benign. The variant received -9 ACMG points: 0P and 9B. BP4_Strong BS1_Supporting BS2

The NM_000391.4(TPP1):​c.*1540T>C variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00346 in 152,334 control chromosomes in the GnomAD database, including 5 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.0035 (5 hom., cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: TPP1 NM_000391.4 3_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.37
• Publications: 0 publications found

Genes affected

TPP1 (HGNC:2073): (tripeptidyl peptidase 1) This gene encodes a member of the sedolisin family of serine proteases. The protease functions in the lysosome to cleave N-terminal tripeptides from substrates, and has weaker endopeptidase activity. It is synthesized as a catalytically-inactive enzyme which is activated and auto-proteolyzed upon acidification. Mutations in this gene result in late-infantile neuronal ceroid lipofuscinosis, which is associated with the failure to degrade specific neuropeptides and a subunit of ATP synthase in the lysosome. [provided by RefSeq, Jul 2008]

TPP1 Gene-Disease associations (from GenCC):

• neuronal ceroid lipofuscinosis

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• neuronal ceroid lipofuscinosis 2

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Myriad Women’s Health, G2P, Orphanet
• autosomal recessive spinocerebellar ataxia 7

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ENSG00000285338 (HGNC:):

ACMG classification

Our verdict: Benign. The variant received -9 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.78).
• BS1: Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.00346 (527/152334) while in subpopulation AFR AF = 0.012 (500/41560). AF 95% confidence interval is 0.0112. There are 5 homozygotes in GnomAd4. There are 253 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting
• BS2: High Homozygotes in GnomAd4 at 5 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TPP1	NM_000391.4	c.*1540T>C		3_prime_UTR_variant	Exon 13 of 13	ENST00000299427.12	NP_000382.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TPP1	ENST00000299427.12	c.*1540T>C		3_prime_UTR_variant	Exon 13 of 13	1	NM_000391.4	ENSP00000299427.6

Frequencies

GnomAD3 genomes AF: 0.00344 AC: 523 AN: 152216 Hom.: 5 Cov.: 32

Gnomad AFR AF: 0.0120

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000982

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000207

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000588

Gnomad OTH AF: 0.00334

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 422 Hom.: 0 Cov.: 0 AF XY: 0.00 AC XY: 0 AN XY: 256

African (AFR) AC: 0 AN: 0

American (AMR) AC: 0 AN: 0

Ashkenazi Jewish (ASJ) AC: 0 AN: 0

East Asian (EAS) AF: 0.00 AC: 0 AN: 2

South Asian (SAS) AC: 0 AN: 0

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 398

Middle Eastern (MID) AC: 0 AN: 0

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 12

Other (OTH) AF: 0.00 AC: 0 AN: 10

GnomAD4 genome AF: 0.00346 AC: 527 AN: 152334 Hom.: 5 Cov.: 32 AF XY: 0.00340 AC XY: 253 AN XY: 74492

African (AFR) AF: 0.0120 AC: 500 AN: 41560

American (AMR) AF: 0.000980 AC: 15 AN: 15300

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

East Asian (EAS) AF: 0.00 AC: 0 AN: 5190

South Asian (SAS) AF: 0.000207 AC: 1 AN: 4826

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10626

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.0000588 AC: 4 AN: 68038

Other (OTH) AF: 0.00331 AC: 7 AN: 2116

Alfa AF: 0.00319 Hom.: 0

Bravo AF: 0.00390

Asia WGS AF: 0.00144 AC: 5 AN: 3478

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Neuronal ceroid lipofuscinosis 2 Uncertain:1

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.78
CADD	Benign	12
DANN	Benign	0.59
PhyloP100		1.4
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1

Splicing

Name	Calibrated prediction	Score	Prediction
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: rs374146578; hg19: chr11-6634237;