chr2-72891345-AG-A

Variant names:

• chr2-72891345-AG-A
• rs1553498582
• NM_003124.5:c.596delG

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PVS1_Strong PM2 PP5_Moderate

The ENST00000234454.6(SPR):​c.596-1delG variant causes a splice acceptor, intron change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 1/1 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: SPR ENST00000234454.6 splice_acceptor, intron
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 9.20
• Publications: 0 publications found

Genes affected

SPR (HGNC:11257): (sepiapterin reductase) This gene encodes an aldo-keto reductase that catalyzes the NADPH-dependent reduction of pteridine derivatives and is important in the biosynthesis of tetrahydrobiopterin (BH4). Mutations in this gene result in DOPA-responsive dystonia due to sepiaterin reductase deficiency. A pseudogene has been identified on chromosome 1. [provided by RefSeq, Jul 2008]

SPR Gene-Disease associations (from GenCC):

• dopa-responsive dystonia due to sepiapterin reductase deficiency

  Inheritance: AD, AR Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet, ClinGen, G2P, Ambry Genetics
• BH4-deficient hyperphenylalaninemia A

  Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 1.0330789 fraction of the gene. Cryptic splice site detected, with MaxEntScore 8.9, offset of 0 (no position change), new splice context is: gtctccttttcatcctctAGtcc. Cryptic site results in inframe change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 2-72891345-AG-A is Pathogenic according to our data. Variant chr2-72891345-AG-A is described in ClinVar as Pathogenic. ClinVar VariationId is 522878.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: ENST00000234454.6. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SPR	NM_003124.5	MANE Select	c.596delG	p.Gly199fs	frameshift splice_region	Exon 3 of 3	NP_003115.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SPR	ENST00000234454.6	TSL:1 MANE Select	c.596-1delG		splice_acceptor intron	N/A	ENSP00000234454.5
	SPR	ENST00000871611.1		c.596-16delG		intron	N/A	ENSP00000541670.1
	SPR	ENST00000871609.1		c.572-1delG		splice_acceptor intron	N/A	ENSP00000541668.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

ClinVar submissions as Germline

Significance: Pathogenic

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
1	-	-	Dopa-responsive dystonia due to sepiapterin reductase deficiency (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		9.2
Mutation Taster		=2/98	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.99		Position offset: 3
DS_AL_spliceai		1.0		Position offset: 2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs1553498582; hg19: chr2-73118474;