rs118204104

chr11-119088638-G-A

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PM1 PM2 PM5 PP3_Strong PP5

The NM_000190.4(HMBS):c.91G>A(p.Ala31Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,208 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A31P) has been classified as Likely pathogenic.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: HMBS NM_000190.4 missense
• Clinical Significance: Pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 8.83

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]

ACMG classification

Verdict is Pathogenic. Variant got 11 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 6 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 chrnull-null-null-null is described in UniProt as null.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.992
• PP5: Variant 11-119088638-G-A is Pathogenic according to our data. Variant chr11-119088638-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 1454.Status of the report is no_assertion_criteria_provided, 0 stars. Variant chr11-119088638-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
HMBS	NM_000190.4	c.91G>A	p.Ala31Thr	missense_variant	3/14	ENST00000652429.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
HMBS	ENST00000652429.1	c.91G>A	p.Ala31Thr	missense_variant	3/14		NM_000190.4	P3

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152208 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 32

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152208 Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1 AN XY: 74358

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

Submissions by phenotype

Acute intermittent porphyria Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Jan 01, 1994

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.59	D
BayesDel_noAF	Pathogenic	0.61
Cadd	Pathogenic	30
Dann	Uncertain	1.0
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.97
FATHMM_MKL	Pathogenic	0.98	D
M_CAP	Pathogenic	0.64	D
MetaRNN	Pathogenic	0.99	D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	0.90	D
MutationTaster	Benign	1.0	A;A;A;A;A;A;A
PrimateAI	Uncertain	0.72	T
REVEL	Pathogenic	0.98
Polyphen		1.0	.;D;.;.;.;.;.;D;.;.;.;.;.
Vest4		0.98, 0.98, 0.89, 0.89, 0.89, 0.98
MutPred		0.98		Gain of methylation at K27 (P = 0.068);Gain of methylation at K27 (P = 0.068);.;.;Gain of methylation at K27 (P = 0.068);.;Gain of methylation at K27 (P = 0.068);.;.;.;.;.;.;
MVP		0.97
MPC		1.1
ClinPred		1.0	D
GERP RS		5.1
RBP_binding_hub_radar		0.97
RBP_regulation_power_radar		2.7
Varity_R		0.98

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs118204104; hg19: chr11-118959348;