rs72557937

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PP3_Moderate

The NM_001395413.1(POR):​c.841C>A​(p.Pro281Thr) variant causes a missense change. The variant allele was found at a frequency of 0.0000223 in 1,612,890 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P281L) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00015 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000089 ( 0 hom. )

Consequence

POR
NM_001395413.1 missense

Scores

7
9
1

Clinical Significance

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

Conservation

PhyloP100: 5.95

Publications

6 publications found
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]
POR Gene-Disease associations (from GenCC):
  • Antley-Bixler syndrome with genital anomalies and disordered steroidogenesis
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: ClinGen, PanelApp Australia, Ambry Genetics
  • congenital adrenal hyperplasia due to cytochrome P450 oxidoreductase deficiency
    Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet
  • Antley-Bixler syndrome
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PP3
MetaRNN computational evidence supports a deleterious effect, 0.842

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
PORNM_001395413.1 linkc.841C>A p.Pro281Thr missense_variant Exon 9 of 16 ENST00000461988.6 NP_001382342.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
PORENST00000461988.6 linkc.841C>A p.Pro281Thr missense_variant Exon 9 of 16 1 NM_001395413.1 ENSP00000419970.2 P16435

Frequencies

GnomAD3 genomes
AF:
0.000151
AC:
23
AN:
152106
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.000555
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:
0.0000402
AC:
10
AN:
248958
AF XY:
0.0000296
show subpopulations
Gnomad AFR exome
AF:
0.000582
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:
0.00
Gnomad OTH exome
AF:
0.000166
GnomAD4 exome
AF:
0.00000890
AC:
13
AN:
1460666
Hom.:
0
Cov.:
32
AF XY:
0.00000826
AC XY:
6
AN XY:
726598
show subpopulations
African (AFR)
AF:
0.000358
AC:
12
AN:
33476
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26128
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86256
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52584
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5764
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111684
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60352
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.471
Heterozygous variant carriers
0
1
2
2
3
4
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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:
0.000151
AC:
23
AN:
152224
Hom.:
0
Cov.:
33
AF XY:
0.0000940
AC XY:
7
AN XY:
74442
show subpopulations
African (AFR)
AF:
0.000554
AC:
23
AN:
41536
American (AMR)
AF:
0.00
AC:
0
AN:
15282
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5174
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4818
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10614
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68018
Other (OTH)
AF:
0.00
AC:
0
AN:
2108
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.516
Heterozygous variant carriers
0
1
3
4
6
7
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<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:
0.00135
Hom.:
0
Bravo
AF:
0.000215
ESP6500AA
AF:
0.000487
AC:
2
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.0000413
AC:
5

ClinVar

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

Submissions by phenotype

not specified Uncertain:1
Jul 24, 2023
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.841C>A (p.Pro281Thr) results in a non-conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4e-05 in 248958 control chromosomes in gnomAD. This frequency is not significantly higher than estimated for a pathogenic variant in POR causing Congenital Adrenal Hyperplasia (4e-05 vs 0.00091), allowing no conclusion about variant significance. To our knowledge, no occurrence of c.841C>A in individuals affected with Congenital Adrenal Hyperplasia has been reported. At least one publication reports experimental evidence evaluating an impact on protein function. Comparing to normal activity of WT, this variant results in 32% of NADPH oxidation and 16% of Cytochrome C reduction in in-vitro assays (example: Huang_2008). Other indirect evidence suggests this variant reduced activity of various P450 enzymes (example: Agrawal_2008). The following publications have been ascertained in the context of this evaluation (PMID: 18551037, 18230729). One submitter has cited clinical-significance assessments for this variant to ClinVar after 2014 and has classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Congenital adrenal hyperplasia due to cytochrome P450 oxidoreductase deficiency Uncertain:1
Apr 07, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces proline, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 284 of the POR protein (p.Pro284Thr). This variant is present in population databases (rs72557937, gnomAD 0.04%). 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 (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. Experimental studies have shown that this missense change affects POR function (PMID: 18230729, 18551037, 31669572). 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
AlphaMissense
Pathogenic
0.99
BayesDel_addAF
Uncertain
0.056
T
BayesDel_noAF
Pathogenic
0.19
CADD
Uncertain
26
DANN
Uncertain
1.0
Eigen
Uncertain
0.56
Eigen_PC
Uncertain
0.55
FATHMM_MKL
Uncertain
0.96
D
LIST_S2
Uncertain
0.95
.;.;D
M_CAP
Uncertain
0.20
D
MetaRNN
Pathogenic
0.84
D;D;D
MetaSVM
Uncertain
0.39
D
PhyloP100
5.9
PrimateAI
Uncertain
0.76
T
PROVEAN
Pathogenic
-7.8
D;D;D
REVEL
Pathogenic
0.80
Sift
Pathogenic
0.0
D;D;D
Sift4G
Pathogenic
0.0
D;D;D
Vest4
0.84
MVP
0.93
MPC
0.52
ClinPred
0.98
D
GERP RS
4.3
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.8
gMVP
0.82
Mutation Taster
=4/96
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

Publications

Other links and lift over

dbSNP: rs72557937; hg19: chr7-75612857; API