1-40080474-C-T

Variant names:

• chr1-40080474-C-T
• rs386833655
• NM_000310.4:c.550G>A
• PPT1 p.Glu184Lys

Variant summary

Our verdict is Pathogenic. The variant received 22 ACMG points: 22P and 0B. PS3 PM1 PM2 PM5 PP3_Strong PP5_Very_Strong

The NM_000310.4(PPT1):​c.550G>A​(p.Glu184Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000124 in 1,613,574 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 Pathogenic (★★). ClinVar reports functional evidence for this variant: "SCV001229728: Experimental studies have shown that this missense change affects PPT1 function (PMID:11440996)." and additional evidence is available in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. E184V) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000012 (0 hom.)
• Consequence: PPT1 NM_000310.4 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:8
• Conservation: PhyloP100: 2.69
• Publications: 7 publications found

Genes affected

PPT1 (HGNC:9325): (palmitoyl-protein thioesterase 1) The protein encoded by this gene is a small glycoprotein involved in the catabolism of lipid-modified proteins during lysosomal degradation. The encoded enzyme removes thioester-linked fatty acyl groups such as palmitate from cysteine residues. Defects in this gene are a cause of infantile neuronal ceroid lipofuscinosis 1 (CLN1, or INCL) and neuronal ceroid lipofuscinosis 4 (CLN4). Two transcript variants encoding different isoforms have been found for this gene.[provided by RefSeq, Dec 2008]

PPT1 Gene-Disease associations (from GenCC):

• neuronal ceroid lipofuscinosis

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• neuronal ceroid lipofuscinosis 1

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, Genomics England PanelApp, G2P, ClinGen, Myriad Women's Health

ACMG classification

Our verdict: Pathogenic. The variant received 22 ACMG points.

• PS3: PS3 evidence extracted from ClinVar submissions: SCV001229728: Experimental studies have shown that this missense change affects PPT1 function (PMID: 11440996).; SCV005201781: Published functional studies found this variant is associated with significantly reduced enzyme activity (PMID: 11440996);; SCV002648668: Functional studies in patient cells and in vitro studies found cells with this mutation had no detectable enzyme activity (Das AK et al. Hum Mol Genet. 2001; 10(13):1431-9).; SCV003844609: The most pronounced variant effect results in <10% of normal activity (example: Das_2001).
• PM1: In a hotspot region, there are 7 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 8 uncertain in NM_000310.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr1-40080473-T-A is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 1527936.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.955
• PP5: Variant 1-40080474-C-T is Pathogenic according to our data. Variant chr1-40080474-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 56204.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000310.4. 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
	PPT1	NM_000310.4	MANE Select	c.550G>A	p.Glu184Lys	missense	Exon 6 of 9	NP_000301.1	P50897-1
	PPT1	NM_001363695.2		c.550G>A	p.Glu184Lys	missense	Exon 6 of 8	NP_001350624.1	Q5T0S4
	PPT1	NM_001142604.2		c.241G>A	p.Glu81Lys	missense	Exon 3 of 6	NP_001136076.1	P50897-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PPT1	ENST00000642050.2	MANE Select	c.550G>A	p.Glu184Lys	missense	Exon 6 of 9	ENSP00000493153.1	P50897-1
	PPT1	ENST00000433473.8	TSL:1	c.547G>A	p.Glu183Lys	missense	Exon 6 of 9	ENSP00000394863.4	A0A2C9F2P4
	PPT1	ENST00000530704.6	TSL:1	n.*173G>A		non_coding_transcript_exon	Exon 6 of 9	ENSP00000431655.1	E9PK48

Frequencies

GnomAD3 genomes AF: 0.0000132 AC: 2 AN: 151930 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000242

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000159 AC: 4 AN: 251404 AF XY: 0.0000147

Gnomad AFR exome AF: 0.000123

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000123 AC: 18 AN: 1461644 Hom.: 0 Cov.: 32 AF XY: 0.0000110 AC XY: 8 AN XY: 727130

African (AFR) AF: 0.0000597 AC: 2 AN: 33476

American (AMR) AF: 0.0000224 AC: 1 AN: 44716

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

East Asian (EAS) AF: 0.00 AC: 0 AN: 39688

South Asian (SAS) AF: 0.0000232 AC: 2 AN: 86248

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53388

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

European-Non Finnish (NFE) AF: 0.0000117 AC: 13 AN: 1111856

Other (OTH) AF: 0.00 AC: 0 AN: 60374

GnomAD4 genome AF: 0.0000132 AC: 2 AN: 151930 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74190

African (AFR) AF: 0.0000242 AC: 1 AN: 41354

American (AMR) AF: 0.00 AC: 0 AN: 15246

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5162

South Asian (SAS) AF: 0.00 AC: 0 AN: 4820

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10552

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

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68006

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

Alfa AF: 0.0000139 Hom.: 0

Bravo AF: 0.0000151

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
4	-	-	Neuronal ceroid lipofuscinosis 1 (4)
2	-	-	not provided (2)
1	-	-	Inborn genetic diseases (1)
1	-	-	Neuronal ceroid lipofuscinosis (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.74
BayesDel_addAF	Pathogenic	0.18	D
BayesDel_noAF	Pathogenic	0.25
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.89	D
Eigen	Benign	-0.031
Eigen_PC	Benign	-0.038
FATHMM_MKL	Uncertain	0.90	D
LIST_S2	Pathogenic	0.99	D
M_CAP	Uncertain	0.27	D
MetaRNN	Pathogenic	0.95	D
MetaSVM	Uncertain	0.34	D
MutationAssessor	Uncertain	2.5	M
PhyloP100		2.7
PrimateAI	Uncertain	0.53	T
PROVEAN	Benign	-1.7	N
REVEL	Pathogenic	0.73
Sift	Uncertain	0.029	D
Sift4G	Uncertain	0.027	D
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.93
gMVP		0.52
Mutation Taster		=26/74	disease causing (ClinVar)

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

dbSNP: rs386833655;

hg19: chr1-40546146;

COSMIC: COSV65655081;

COSMIC: COSV65655081;