10-71817165-C-T

Variant names:

• chr10-71817165-C-T
• rs547409137
• NM_002778.4:c.*276G>A

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP4_Strong BS1_Supporting

The NM_002778.4(PSAP):​c.*276G>A variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00013 in 537,472 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.000066 (0 hom., cov: 33)
  • Exomes 𝑓: 0.00016 (0 hom.)
• Consequence: PSAP NM_002778.4 3_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:4
• Conservation: PhyloP100: 0.266
• 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: Likely_benign. The variant received -5 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.69).
• BS1: Variant frequency is greater than expected in population mid. GnomAdExome4 allele frequency = 0.000156 (60/385134) while in subpopulation MID AF = 0.00279 (5/1790). AF 95% confidence interval is 0.0011. There are 0 homozygotes in GnomAdExome4. There are 39 alleles in the male GnomAdExome4 subpopulation. Median coverage is 0. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PSAP	NM_002778.4	c.*276G>A		3_prime_UTR_variant	Exon 14 of 14	ENST00000394936.8	NP_002769.1
PSAP	NM_001042465.3	c.*276G>A		3_prime_UTR_variant	Exon 15 of 15		NP_001035930.1
PSAP	NM_001042466.3	c.*276G>A		3_prime_UTR_variant	Exon 15 of 15		NP_001035931.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PSAP	ENST00000394936.8	c.*276G>A		3_prime_UTR_variant	Exon 14 of 14	1	NM_002778.4	ENSP00000378394.3

Frequencies

GnomAD3 genomes AF: 0.0000657 AC: 10 AN: 152220 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

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: 0.000118

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.000156 AC: 60 AN: 385134 Hom.: 0 Cov.: 0 AF XY: 0.000190 AC XY: 39 AN XY: 204868

African (AFR) AF: 0.000181 AC: 2 AN: 11038

American (AMR) AF: 0.0000600 AC: 1 AN: 16678

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 11796

East Asian (EAS) AF: 0.00 AC: 0 AN: 25052

South Asian (SAS) AF: 0.000408 AC: 18 AN: 44110

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 22514

Middle Eastern (MID) AF: 0.00279 AC: 5 AN: 1790

European-Non Finnish (NFE) AF: 0.000122 AC: 28 AN: 230028

Other (OTH) AF: 0.000271 AC: 6 AN: 22128

GnomAD4 genome AF: 0.0000656 AC: 10 AN: 152338 Hom.: 0 Cov.: 33 AF XY: 0.0000671 AC XY: 5 AN XY: 74494

African (AFR) AF: 0.0000241 AC: 1 AN: 41572

American (AMR) AF: 0.00 AC: 0 AN: 15312

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

East Asian (EAS) AF: 0.00 AC: 0 AN: 5180

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

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10620

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 292

European-Non Finnish (NFE) AF: 0.000118 AC: 8 AN: 68040

Other (OTH) AF: 0.00 AC: 0 AN: 2114

Alfa AF: 0.000285 Hom.: 0

Bravo AF: 0.0000756

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

Jan 12, 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. -

Combined PSAP deficiency Uncertain:1

Jan 12, 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. -

Krabbe disease due to saposin A deficiency Uncertain:1

Jan 12, 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. -

Sphingolipid activator protein 1 deficiency Uncertain:1

Jan 12, 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	-0.69
CADD	Benign	7.4
DANN	Benign	0.78
PhyloP100		0.27

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: rs547409137; hg19: chr10-73576922;