10-71816433-G-A

Variant summary

Our verdict is Benign. Variant got -8 ACMG points: 0P and 8B. BP4_Strong BS2

The NM_002778.4(PSAP):c.*1008C>T variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00007 in 471,118 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.000053 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000078 (1 hom.)
• Consequence: PSAP NM_002778.4 3_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:4
• Conservation: PhyloP100: -1.10

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]

ACMG classification

Verdict is Benign. Variant got -8 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.83).
• BS2: High AC in GnomAd at 8 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PSAP	NM_002778.4	c.*1008C>T		3_prime_UTR_variant	14/14	ENST00000394936.8
PSAP	NM_001042465.3	c.*1008C>T		3_prime_UTR_variant	15/15
PSAP	NM_001042466.3	c.*1008C>T		3_prime_UTR_variant	15/15

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PSAP	ENST00000394936.8	c.*1008C>T		3_prime_UTR_variant	14/14	1	NM_002778.4	P1

Frequencies

GnomAD3 genomes AF: 0.0000526 AC: 8 AN: 152230 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000482

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: 0.0000882

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000527 AC: 8 AN: 151768 Hom.: 0 AF XY: 0.0000491 AC XY: 4 AN XY: 81522

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000185

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.000104

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000784 AC: 25 AN: 318888 Hom.: 1 Cov.: 0 AF XY: 0.0000777 AC XY: 14 AN XY: 180160

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.000217

Gnomad4 SAS exome AF: 0.0000502

Gnomad4 FIN exome AF: 0.0000738

Gnomad4 NFE exome AF: 0.000101

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000526 AC: 8 AN: 152230 Hom.: 0 Cov.: 33 AF XY: 0.0000538 AC XY: 4 AN XY: 74358

Gnomad4 AFR AF: 0.0000482

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000882

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000959 Hom.: 0

Bravo AF: 0.0000491

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, single submitter

Submissions by phenotype

Gaucher disease due to saposin C deficiency Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

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. -

Combined PSAP deficiency Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

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. -

Krabbe disease due to saposin A deficiency Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

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. -

Sphingolipid activator protein 1 deficiency Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

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	-0.83
Cadd	Benign	0.19
Dann	Benign	0.61
RBP_binding_hub_radar		1.1
RBP_regulation_power_radar		2.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs537171961; hg19: chr10-73576190;