chr11-119092506-G-A

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2PP3_Strong

The NM_000190.4(HMBS):​c.754G>A​(p.Ala252Thr) variant causes a missense change. The variant allele was found at a frequency of 0.0000105 in 1,614,090 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 Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000010 ( 0 hom. )

Consequence

HMBS
NM_000190.4 missense

Scores

8
5
5

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts P:1U:3

Conservation

PhyloP100: 6.62
Variant links:
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]

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ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.979

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
HMBSNM_000190.4 linkuse as main transcriptc.754G>A p.Ala252Thr missense_variant 11/14 ENST00000652429.1 NP_000181.2

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
HMBSENST00000652429.1 linkuse as main transcriptc.754G>A p.Ala252Thr missense_variant 11/14 NM_000190.4 ENSP00000498786 P3P08397-1

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152228
Hom.:
0
Cov.:
32
show subpopulations
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:
0.00316
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.00000796
AC:
2
AN:
251354
Hom.:
0
AF XY:
0.00000736
AC XY:
1
AN XY:
135846
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000103
AC:
15
AN:
1461862
Hom.:
0
Cov.:
32
AF XY:
0.0000124
AC XY:
9
AN XY:
727240
show subpopulations
Gnomad4 AFR exome
AF:
0.0000299
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.0000252
Gnomad4 SAS exome
AF:
0.0000116
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00000360
Gnomad4 OTH exome
AF:
0.0000166
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152228
Hom.:
0
Cov.:
32
AF XY:
0.0000269
AC XY:
2
AN XY:
74372
show subpopulations
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
Bravo
AF:
0.0000151

ClinVar

Significance: Uncertain significance
Submissions summary: Pathogenic:1Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Acute intermittent porphyria Pathogenic:1Uncertain:2
Uncertain significance, criteria provided, single submitterclinical testingIllumina Laboratory Services, IlluminaApr 27, 2017This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). Publications were found based on this search. However, the evidence from the literature, in combination with allele frequency data from public databases where available, was not sufficient to rule this variant in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -
Pathogenic, no assertion criteria providedliterature onlyOMIMDec 01, 1993- -
Uncertain significance, criteria provided, single submitterclinical testingCenter for Genomic Medicine, King Faisal Specialist Hospital and Research CenterMar 26, 2024- -
not provided Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpApr 12, 2023This variant is present in population databases (rs118204113, gnomAD 0.002%). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. This variant disrupts the p.Ala252 amino acid residue in HMBS. Other variant(s) that disrupt this residue have been observed in individuals with HMBS-related conditions (PMID: 8262523, 9067752), which suggests that this may be a clinically significant amino acid residue. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt HMBS protein function. ClinVar contains an entry for this variant (Variation ID: 1472). This missense change has been observed in individual(s) with acute intermittent porphyria (PMID: 8262523). This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 252 of the HMBS protein (p.Ala252Thr). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.30
BayesDel_addAF
Pathogenic
0.51
D
BayesDel_noAF
Pathogenic
0.50
CADD
Uncertain
25
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.90
.;D;.;D;.;.;.;.
Eigen
Uncertain
0.31
Eigen_PC
Uncertain
0.38
FATHMM_MKL
Pathogenic
0.98
D
M_CAP
Pathogenic
0.36
D
MetaRNN
Pathogenic
0.98
D;D;D;D;D;D;D;D
MetaSVM
Pathogenic
1.2
D
MutationAssessor
Uncertain
2.6
.;M;.;.;.;.;.;.
MutationTaster
Benign
1.0
A;A;A;A;A;A;A
PrimateAI
Uncertain
0.61
T
PROVEAN
Benign
-1.8
.;N;N;N;.;.;N;.
REVEL
Pathogenic
0.79
Sift
Benign
0.057
.;T;D;D;.;.;D;.
Sift4G
Benign
0.076
.;T;T;T;.;.;T;.
Polyphen
0.40, 0.35
.;B;.;B;.;.;.;.
Vest4
0.85, 0.88, 0.81, 0.87
MutPred
0.94
.;Loss of catalytic residue at A252 (P = 0.1094);.;.;.;.;.;.;
MVP
0.99
MPC
0.99
ClinPred
0.79
D
GERP RS
4.3
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.57

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs118204113; hg19: chr11-118963216; API