NM_000374.5:c.636+1G>A

Variant names:

• chr1-45014071-G-A
• rs145195562
• NM_000374.5:c.636+1G>A

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PVS1_Strong PM2

The NM_000374.5(UROD):​c.636+1G>A variant causes a splice donor, intron 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. 3/3 splice prediction tools predicting alterations to normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: not found (cov: 32)
• Consequence: UROD NM_000374.5 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.01
• Publications: 4 publications found

Genes affected

UROD (HGNC:12591): (uroporphyrinogen decarboxylase) This gene encodes an enzyme in the heme biosynthetic pathway. This enzyme is responsible for catalyzing the conversion of uroporphyrinogen to coproporphyrinogen through the removal of four carboxymethyl side chains. Mutations and deficiency in this enzyme are known to cause familial porphyria cutanea tarda and hepatoerythropoetic porphyria.[provided by RefSeq, Aug 2010]

UROD Gene-Disease associations (from GenCC):

• UROD-related inherited porphyria

  Inheritance: SD Classification: DEFINITIVE Submitted by: ClinGen, Ambry Genetics
• familial porphyria cutanea tarda

  Inheritance: AD, AR Classification: STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet, Labcorp Genetics (formerly Invitae)
• hepatoerythropoietic porphyria

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.14673913 fraction of the gene. Cryptic splice site detected, with MaxEntScore 6.8, offset of -27, new splice context is: ctgGTagga. Cryptic site results in inframe change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000374.5. 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
	UROD	NM_000374.5	MANE Select	c.636+1G>A		splice_donor intron	N/A	NP_000365.3
	UROD	NR_036510.2		n.698+1G>A		splice_donor intron	N/A
	UROD	NR_158184.1		n.717+1G>A		splice_donor intron	N/A

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	UROD	ENST00000246337.9	TSL:1 MANE Select	c.636+1G>A		splice_donor intron	N/A	ENSP00000246337.4
	UROD	ENST00000460906.5	TSL:5	n.771G>A		non_coding_transcript_exon	Exon 5 of 5
	UROD	ENST00000472254.1	TSL:2	n.22G>A		non_coding_transcript_exon	Exon 1 of 4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.62	D
BayesDel_noAF	Pathogenic	0.31
CADD	Pathogenic	34
DANN	Uncertain	0.99
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.1
FATHMM_MKL	Pathogenic	0.98	D
PhyloP100		9.0
GERP RS		5.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		2.7
Mutation Taster		=0/100	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		0.90		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.48		Position offset: -28
DS_DL_spliceai		0.90		Position offset: -1

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

Other links and lift over

dbSNP: rs145195562; hg19: chr1-45479743;