10-71829003-G-T

Variant names:

• chr10-71829003-G-T
• rs757752213
• NM_002778.4:c.450C>A

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_002778.4(PSAP):​c.450C>A​(p.His150Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000144 in 1,461,864 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 17/22 in silico tools predict a benign 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. H150Y) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.000014 (0 hom.)
• Consequence: PSAP NM_002778.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:2
• Conservation: PhyloP100: 0.725
• Publications: 0 publications found

Genes affected

PSAP (HGNC:9498): (prosaposin) This gene encodes a highly conserved preproprotein that is proteolytically processed to generate four main cleavage products including saposins A, B, C, and D. Each domain of the precursor protein is approximately 80 amino acid residues long with nearly identical placement of cysteine residues and glycosylation sites. Saposins A-D localize primarily to the lysosomal compartment where they facilitate the catabolism of glycosphingolipids with short oligosaccharide groups. The precursor protein exists both as a secretory protein and as an integral membrane protein and has neurotrophic activities. Mutations in this gene have been associated with Gaucher disease and metachromatic leukodystrophy. Alternative splicing results in multiple transcript variants, at least one of which encodes an isoform that is proteolytically processed. [provided by RefSeq, Feb 2016]

PSAP Gene-Disease associations (from GenCC):

• combined PSAP deficiency

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp, ClinGen, Labcorp Genetics (formerly Invitae)
• Gaucher disease due to saposin C deficiency

  Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Genomics England PanelApp, Ambry Genetics, Labcorp Genetics (formerly Invitae), ClinGen
• Krabbe disease due to saposin A deficiency

  Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE, LIMITED Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), ClinGen, G2P
• metachromatic leukodystrophy due to saposin B deficiency

  Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Genomics England PanelApp, Ambry Genetics, Labcorp Genetics (formerly Invitae), ClinGen
• Parkinson disease 24, autosomal dominant, susceptibility to

  Inheritance: Unknown Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.08202669).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PSAP	NM_002778.4	c.450C>A	p.His150Gln	missense_variant	Exon 5 of 14	ENST00000394936.8	NP_002769.1
PSAP	NM_001042465.3	c.450C>A	p.His150Gln	missense_variant	Exon 5 of 15		NP_001035930.1
PSAP	NM_001042466.3	c.450C>A	p.His150Gln	missense_variant	Exon 5 of 15		NP_001035931.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PSAP	ENST00000394936.8	c.450C>A	p.His150Gln	missense_variant	Exon 5 of 14	1	NM_002778.4	ENSP00000378394.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.0000144 AC: 21 AN: 1461864 Hom.: 0 Cov.: 31 AF XY: 0.0000165 AC XY: 12 AN XY: 727240

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

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

European-Non Finnish (NFE) AF: 0.0000189 AC: 21 AN: 1111984

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, single submitter

Submissions by phenotype

Sphingolipid activator protein 1 deficiency Uncertain:1

Aug 27, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Metachromatic leukodystrophy Uncertain:1

Oct 22, 2020

Natera, Inc.

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.10
BayesDel_addAF	Benign	-0.20	T
BayesDel_noAF	Benign	-0.52
CADD	Benign	16
DANN	Benign	0.82
DEOGEN2	Benign	0.21	T;T
Eigen	Benign	-0.57
Eigen_PC	Benign	-0.39
FATHMM_MKL	Uncertain	0.81	D
LIST_S2	Benign	0.65	T;T
M_CAP	Benign	0.0093	T
MetaRNN	Benign	0.082	T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	-0.55	N;.
PhyloP100		0.72
PrimateAI	Benign	0.32	T
PROVEAN	Benign	-0.84	N;N
REVEL	Benign	0.047
Sift	Benign	0.57	T;T
Sift4G	Benign	0.65	T;T
Polyphen		0.0	B;.
Vest4		0.13
MutPred		0.24		Gain of methylation at K152 (P = 0.1022);Gain of methylation at K152 (P = 0.1022);
MVP		0.41
MPC		0.041
ClinPred		0.090	T
GERP RS		2.4
Varity_R		0.052
gMVP		0.30
Mutation Taster		=89/11	polymorphism

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

Other links and lift over

dbSNP: rs757752213; hg19: chr10-73588760;