rs786205245

Variant names:

• chr18-57554259-C-T
• rs786205245
• NM_000140.5:c.1077+1G>A

Your query was ambiguous. Multiple possible variants found:

• chr18-57554259-C-T
• chr18-57554259-C-A

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PVS1_Strong PM2 PP5

The NM_000140.5(FECH):​c.1077+1G>A variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,876 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (no stars).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: FECH NM_000140.5 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 7.40
• Publications: 1 publications found

Genes affected

FECH (HGNC:3647): (ferrochelatase) The protein encoded by this gene is localized to the mitochondrion, where it catalyzes the insertion of the ferrous form of iron into protoporphyrin IX in the heme synthesis pathway. Mutations in this gene are associated with erythropoietic protoporphyria. Two transcript variants encoding different isoforms have been found for this gene. A pseudogene of this gene is found on chromosome 3.[provided by RefSeq, May 2010]

FECH Gene-Disease associations (from GenCC):

• protoporphyria, erythropoietic, 1

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: ClinGen, Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
• autosomal erythropoietic protoporphyria

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.12971698 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 18-57554259-C-T is Pathogenic according to our data. Variant chr18-57554259-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 552.Status of the report is no_assertion_criteria_provided, 0 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000140.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	FECH	NM_000140.5	MANE Select	c.1077+1G>A		splice_donor intron	N/A	NP_000131.2	P22830-1
	FECH	NM_001012515.4		c.1095+1G>A		splice_donor intron	N/A	NP_001012533.1	P22830-2
	FECH	NM_001374778.1		c.1077+1G>A		splice_donor intron	N/A	NP_001361707.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	FECH	ENST00000262093.11	TSL:1 MANE Select	c.1077+1G>A		splice_donor intron	N/A	ENSP00000262093.6	P22830-1
	FECH	ENST00000652755.1		c.1095+1G>A		splice_donor intron	N/A	ENSP00000498358.1	P22830-2
	FECH	ENST00000878110.1		c.1077+1G>A		splice_donor intron	N/A	ENSP00000548169.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461876 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727242

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

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: 53420

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

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111994

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

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 33

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: no assertion criteria provided

Pathogenic	VUS	Benign	Condition
1	-	-	Protoporphyria, erythropoietic, 1 (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.45
CADD	Pathogenic	32
DANN	Uncertain	1.0
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.1
FATHMM_MKL	Pathogenic	0.98	D
PhyloP100		7.4
GERP RS		6.2
Mutation Taster		=0/100	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		0.92		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.92		Position offset: 1

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

Other links and lift over

dbSNP: rs786205245; hg19: chr18-55221491;