1-40074096-A-T

Variant names:

• chr1-40074096-A-T
• NM_000310.4:c.886T>A
• PPT1 p.Trp296Arg

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PS1 PM2 PP3_Moderate

The NM_000310.4(PPT1):​c.886T>A​(p.Trp296Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another nucleotide change resulting in the same amino acid substitution has been previously reported as Likely pathogenic in ClinVar.

• Frequency: Genomes: not found (cov: 32)
• Consequence: PPT1 NM_000310.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.07
• Publications: 0 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: Likely_pathogenic. The variant received 8 ACMG points.

• PS1: Transcript NM_000310.4 (PPT1) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in ClinVar.
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.934

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.886T>A	p.Trp296Arg	missense	Exon 9 of 9	NP_000301.1	P50897-1
	PPT1	NM_001363695.2		c.814T>A	p.Trp272Arg	missense	Exon 8 of 8	NP_001350624.1	Q5T0S4
	PPT1	NM_001142604.2		c.577T>A	p.Trp193Arg	missense	Exon 6 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.886T>A	p.Trp296Arg	missense	Exon 9 of 9	ENSP00000493153.1	P50897-1
	PPT1	ENST00000433473.8	TSL:1	c.883T>A	p.Trp295Arg	missense	Exon 9 of 9	ENSP00000394863.4	A0A2C9F2P4
	PPT1	ENST00000530704.6	TSL:1	n.*509T>A		non_coding_transcript_exon	Exon 9 of 9	ENSP00000431655.1	E9PK48

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.90
BayesDel_addAF	Pathogenic	0.56	D
BayesDel_noAF	Pathogenic	0.57
CADD	Pathogenic	27
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.95	D
Eigen	Pathogenic	0.76
Eigen_PC	Pathogenic	0.75
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Benign	0.80	T
M_CAP	Uncertain	0.25	D
MetaRNN	Pathogenic	0.93	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	3.5	H
PhyloP100		9.1
PrimateAI	Uncertain	0.63	T
PROVEAN	Pathogenic	-12	D
REVEL	Pathogenic	0.87
Sift	Uncertain	0.025	D
Sift4G	Pathogenic	0.0	D
Varity_R		0.99
gMVP		0.85
Mutation Taster		=2/98	disease causing

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

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

Other links and lift over

hg19: chr1-40539768;