NM_000190.4:c.754G>C

Variant names:

• chr11-119092506-G-C
• rs118204113
• NM_000190.4:c.754G>C

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Very_Strong

The NM_000190.4(HMBS):​c.754G>C​(p.Ala252Pro) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A252V) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: HMBS NM_000190.4 missense
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 6.62
• Publications: 0 publications found

Genes affected

HMBS (HGNC:4982): (hydroxymethylbilane synthase) This gene encodes a member of the hydroxymethylbilane synthase superfamily. The encoded protein is the third enzyme of the heme biosynthetic pathway and catalyzes the head to tail condensation of four porphobilinogen molecules into the linear hydroxymethylbilane. Mutations in this gene are associated with the autosomal dominant disease acute intermittent porphyria. Alternatively spliced transcript variants encoding different isoforms have been described. [provided by RefSeq, Jul 2008]

HMBS Gene-Disease associations (from GenCC):

• acute intermittent porphyria

  Inheritance: SD, AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: ClinGen, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 18 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 10 uncertain in NM_000190.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr11-119092507-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 1473.Status of the report is no_assertion_criteria_provided, 0 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.98
• PP5: Variant 11-119092506-G-C is Pathogenic according to our data. Variant chr11-119092506-G-C is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 1691435.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000190.4. 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
	HMBS	NM_000190.4	MANE Select	c.754G>C	p.Ala252Pro	missense	Exon 11 of 14	NP_000181.2
	HMBS	NM_001425056.1		c.745G>C	p.Ala249Pro	missense	Exon 11 of 14	NP_001411985.1
	HMBS	NM_001425057.1		c.736G>C	p.Ala246Pro	missense	Exon 11 of 14	NP_001411986.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	HMBS	ENST00000652429.1	MANE Select	c.754G>C	p.Ala252Pro	missense	Exon 11 of 14	ENSP00000498786.1
	HMBS	ENST00000392841.1	TSL:1	c.703G>C	p.Ala235Pro	missense	Exon 11 of 14	ENSP00000376584.1
	HMBS	ENST00000442944.7	TSL:5	c.736G>C	p.Ala246Pro	missense	Exon 11 of 14	ENSP00000392041.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions as Germline

Significance: Likely pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
2	-	-	not provided (2)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.56	D
BayesDel_noAF	Pathogenic	0.56
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.98	D
Eigen	Pathogenic	0.72
Eigen_PC	Uncertain	0.65
FATHMM_MKL	Pathogenic	0.98	D
M_CAP	Pathogenic	0.57	D
MetaRNN	Pathogenic	0.98	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.6	H
PhyloP100		6.6
PrimateAI	Uncertain	0.67	T
PROVEAN	Uncertain	-3.0	D
REVEL	Pathogenic	0.94
Sift	Uncertain	0.0040	D
Sift4G	Uncertain	0.0070	D
Polyphen		0.90	P
Vest4		0.68
MutPred		0.89		Loss of catalytic residue at A252 (P = 0.0596)
MVP		0.98
MPC		1.3
ClinPred		1.0	D
GERP RS		4.3
Varity_R		0.99
Mutation Taster		=6/94	disease causing

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: rs118204113; hg19: chr11-118963216;