NM_000031.6:c.823G>A

Variant names:

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2PP3_Strong

The NM_000031.6(ALAD):c.823G>A(p.Val275Met) variant causes a missense change. The variant allele was found at a frequency of 0.0000167 in 1,613,860 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: 33)

Exomes 𝑓: 0.000017 ( 0 hom. )

Consequence

ALAD
NM_000031.6 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter P:1U:1

Conservation

PhyloP100: 5.68

Publications

13 publications found

Variant links:

Genes affected

ALAD (HGNC:395): (aminolevulinate dehydratase) The ALAD enzyme is composed of 8 identical subunits and catalyzes the condensation of 2 molecules of delta-aminolevulinate to form porphobilinogen (a precursor of heme, cytochromes and other hemoproteins). ALAD catalyzes the second step in the porphyrin and heme biosynthetic pathway; zinc is essential for enzymatic activity. ALAD enzymatic activity is inhibited by lead and a defect in the ALAD structural gene can cause increased sensitivity to lead poisoning and acute hepatic porphyria. Alternative splicing of this gene results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Dec 2015]

ALAD Gene-Disease associations (from GenCC):

porphyria due to ALA dehydratase deficiency
Inheritance: AR Classification: STRONG, MODERATE, SUPPORTIVE, LIMITED Submitted by: Ambry Genetics, Genomics England PanelApp, Orphanet, Labcorp Genetics (formerly Invitae), G2P, ClinGen

ALAD links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

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

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.95

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ALAD	NM_000031.6 link	c.823G>A	p.Val275Met	missense_variant	Exon 11 of 12	ENST00000409155.8	NP_000022.3	P13716-1A0A140VJL9Q6ZMU0

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ALAD	ENST00000409155.8 link	c.823G>A	p.Val275Met	missense_variant	Exon 11 of 12	1	NM_000031.6	ENSP00000386284.3		P13716-1
ALAD	ENST00000482847.5 link	n.1096G>A		non_coding_transcript_exon_variant	Exon 11 of 12	2

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152216

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000482

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000320

AC:

AN:

250350

AF XY:

0.0000369

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 FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000709

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000171

AC:

AN:

1461644

Hom.:

Cov.:

AF XY:

0.0000206

AC XY:

AN XY:

727128

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33478

American (AMR)

AF:

0.00

AC:

AN:

44722

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.0000252

AC:

AN:

39700

South Asian (SAS)

AF:

0.0000464

AC:

AN:

86254

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53186

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.0000162

AC:

AN:

1112008

Other (OTH)

AF:

0.0000331

AC:

AN:

60392

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.479

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152216

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74356

show subpopulations

African (AFR)

AF:

0.0000482

AC:

AN:

41460

American (AMR)

AF:

0.00

AC:

AN:

15284

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5196

South Asian (SAS)

AF:

0.00

AC:

AN:

4834

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10624

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68034

Other (OTH)

AF:

0.00

AC:

AN:

2086

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.525

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.0000438

Hom.:

Bravo

AF:

0.00000756

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:1Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Porphobilinogen synthase deficiency

Pathogenic:1

Jul 01, 1991

OMIM

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:literature only

- -

not provided

Uncertain:1

Jan 31, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

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. Experimental studies have shown that this variant affects ALAD protein function (PMID: 17236137). This variant has been observed in individual(s) with acute hepatic porphyria (PMID: 2063868). ClinVar contains an entry for this variant (Variation ID: 16863). This variant is present in population databases (rs121912981, ExAC 0.002%). This sequence change replaces valine with methionine at codon 275 of the ALAD protein (p.Val275Met). The valine residue is highly conserved and there is a small physicochemical difference between valine and methionine. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.55

BayesDel_addAF

Pathogenic

0.31

BayesDel_noAF

Pathogenic

0.39

CADD

Pathogenic

(source)

DANN

Pathogenic

1.0

DEOGEN2

Uncertain

0.73

Eigen

Pathogenic

0.92

Eigen_PC

Pathogenic

0.86

FATHMM_MKL

Pathogenic

0.97

LIST_S2

Pathogenic

0.99

M_CAP

Uncertain

0.25

MetaRNN

Pathogenic

0.95

MetaSVM

Pathogenic

0.95

MutationAssessor

Pathogenic

3.8

PhyloP100

5.7

PrimateAI

Uncertain

0.60

PROVEAN

Benign

-1.9

REVEL

Pathogenic

0.83

Sift

Uncertain

0.016

Sift4G

Uncertain

0.0070

Polyphen

0.99

Vest4

0.96

MVP

0.95

MPC

1.2

ClinPred

0.94

GERP RS

5.7

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.86

gMVP

0.95

Mutation Taster

=16/84

disease causing (ClinVar)

(source)

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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over