rs72557947

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2BP4_Strong

The NM_001395413.1(POR):​c.1444G>A​(p.Ala482Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000489 in 1,593,634 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/18 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. A482A) has been classified as Benign.

Frequency

Genomes: 𝑓 0.000072 ( 0 hom., cov: 36)
Exomes 𝑓: 0.000046 ( 0 hom. )

Consequence

POR
NM_001395413.1 missense

Scores

16

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 0.388
Variant links:
Genes affected
POR (HGNC:9208): (cytochrome p450 oxidoreductase) This gene encodes an endoplasmic reticulum membrane oxidoreductase that is essential for multiple metabolic processes, including reactions catalyzed by cytochrome P450 proteins for metabolism of steroid hormones, drugs and xenobiotics. The encoded protein has a flavin adenine dinucleotide (FAD)-binding domain and a flavodoxin-like domain which bind two cofactors, FAD and FMN, that allow it to donate electrons directly from NADPH to all microsomal P450 enzymes. Mutations in this gene cause a complex set of disorders, including apparent combined P450C17 and P450C21 deficiency, amenorrhea and disordered steroidogenesis, congenital adrenal hyperplasia and Antley-Bixler syndrome, that resemble those caused by defects in steroid metabolizing enzymes such as aromatase, 21-hydroxylase, and 17 alpha-hydroxylase. [provided by RefSeq, Aug 2020]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -2 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.020320505).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
PORNM_001395413.1 linkc.1444G>A p.Ala482Thr missense_variant Exon 13 of 16 ENST00000461988.6 NP_001382342.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
PORENST00000461988.6 linkc.1444G>A p.Ala482Thr missense_variant Exon 13 of 16 1 NM_001395413.1 ENSP00000419970.2 P16435

Frequencies

GnomAD3 genomes
AF:
0.0000788
AC:
12
AN:
152254
Hom.:
0
Cov.:
36
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:
0.00231
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
GnomAD3 exomes
AF:
0.000104
AC:
23
AN:
221010
Hom.:
0
AF XY:
0.0000912
AC XY:
11
AN XY:
120646
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00131
Gnomad SAS exome
AF:
0.0000370
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000465
AC:
67
AN:
1441262
Hom.:
0
Cov.:
65
AF XY:
0.0000504
AC XY:
36
AN XY:
714606
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00136
Gnomad4 SAS exome
AF:
0.0000843
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00000454
Gnomad4 OTH exome
AF:
0.0000336
GnomAD4 genome
AF:
0.0000722
AC:
11
AN:
152372
Hom.:
0
Cov.:
36
AF XY:
0.0000805
AC XY:
6
AN XY:
74508
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00212
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.00
Gnomad4 OTH
AF:
0.00
Bravo
AF:
0.000113
ExAC
AF:
0.0000672
AC:
8
Asia WGS
AF:
0.000289
AC:
1
AN:
3478

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Uncertain:1
Dec 13, 2024
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Variant summary: POR c.1444G>A (p.Ala482Thr) results in a non-conservative amino acid change in the encoded protein sequence. Two of three in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 0.0001 in 221010 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in POR causing Congenital Adrenal Hyperplasia (0.0001 vs 0.00091), allowing no conclusion about variant significance. To our knowledge, no occurrence of c.1444G>A in individuals affected with Congenital Adrenal Hyperplasia has been reported. At least one publication reports experimental evidence evaluating an impact on protein function, however, does not allow convincing conclusions about the variant effect (Agrawal_2008, Huang_2008). The following publications have been ascertained in the context of this evaluation (PMID: 18551037, 18230729). ClinVar contains an entry for this variant (Variation ID: 1479420). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Congenital adrenal hyperplasia due to cytochrome P450 oxidoreductase deficiency Uncertain:1
Nov 30, 2021
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 485 of the POR protein (p.Ala485Thr). This variant is present in population databases (rs72557947, gnomAD 0.1%). This variant has not been reported in the literature in individuals affected with POR-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The threonine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. Experimental studies are conflicting or provide insufficient evidence to determine the effect of this variant on POR function (PMID: 18230729, 18551037). 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Benign
-0.46
T
BayesDel_noAF
Benign
-0.48
CADD
Benign
0.64
DANN
Benign
0.90
Eigen
Benign
-1.0
Eigen_PC
Benign
-1.1
FATHMM_MKL
Benign
0.36
N
LIST_S2
Benign
0.83
.;.;T
M_CAP
Benign
0.0082
T
MetaRNN
Benign
0.020
T;T;T
MetaSVM
Benign
-0.95
T
PrimateAI
Benign
0.37
T
PROVEAN
Benign
2.7
N;N;N
REVEL
Benign
0.080
Sift
Benign
1.0
T;T;T
Sift4G
Benign
1.0
T;T;T
Vest4
0.045
MVP
0.22
MPC
0.11
ClinPred
0.016
T
GERP RS
-4.4
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
gMVP
0.20

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: rs72557947; hg19: chr7-75614951; API