2-25161217-A-G

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 0P and 1B. BS1_Supporting

The NM_000939.4(POMC):​c.668T>C​(p.Met223Thr) variant causes a missense change. The variant allele was found at a frequency of 0.000031 in 1,613,112 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (no stars).

Frequency

Genomes: 𝑓 0.00014 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000020 ( 0 hom. )

Consequence

POMC
NM_000939.4 missense

Scores

4
13
2

Clinical Significance

Uncertain significance no assertion criteria provided U:1

Conservation

PhyloP100: 5.54

Publications

5 publications found
Variant links:
Genes affected
POMC (HGNC:9201): (proopiomelanocortin) This gene encodes a preproprotein that undergoes extensive, tissue-specific, post-translational processing via cleavage by subtilisin-like enzymes known as prohormone convertases. There are eight potential cleavage sites within the preproprotein and, depending on tissue type and the available convertases, processing may yield as many as ten biologically active peptides involved in diverse cellular functions. The encoded protein is synthesized mainly in corticotroph cells of the anterior pituitary where four cleavage sites are used; adrenocorticotrophin, essential for normal steroidogenesis and the maintenance of normal adrenal weight, and lipotropin beta are the major end products. In other tissues, including the hypothalamus, placenta, and epithelium, all cleavage sites may be used, giving rise to peptides with roles in pain and energy homeostasis, melanocyte stimulation, and immune modulation. These include several distinct melanotropins, lipotropins, and endorphins that are contained within the adrenocorticotrophin and beta-lipotropin peptides. The antimicrobial melanotropin alpha peptide exhibits antibacterial and antifungal activity. Mutations in this gene have been associated with early onset obesity, adrenal insufficiency, and red hair pigmentation. Alternatively spliced transcript variants encoding the same protein have been described. [provided by RefSeq, Jan 2016]
POMC Gene-Disease associations (from GenCC):
  • obesity due to pro-opiomelanocortin deficiency
    Inheritance: AR Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Orphanet, Ambry Genetics
  • inherited obesity
    Inheritance: SD, AD Classification: STRONG, LIMITED Submitted by: Ambry Genetics

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -1 ACMG points.

BS1
Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.000138 (21/151886) while in subpopulation AFR AF = 0.000508 (21/41340). AF 95% confidence interval is 0.00034. There are 0 homozygotes in GnomAd4. There are 7 alleles in the male GnomAd4 subpopulation. Median coverage is 33. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
POMCNM_000939.4 linkc.668T>C p.Met223Thr missense_variant Exon 3 of 3 ENST00000395826.7 NP_000930.1 P01189
POMCNM_001035256.3 linkc.668T>C p.Met223Thr missense_variant Exon 4 of 4 NP_001030333.1 P01189
POMCNM_001319204.2 linkc.668T>C p.Met223Thr missense_variant Exon 4 of 4 NP_001306133.1 P01189
POMCNM_001319205.2 linkc.668T>C p.Met223Thr missense_variant Exon 3 of 3 NP_001306134.1 P01189

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
POMCENST00000395826.7 linkc.668T>C p.Met223Thr missense_variant Exon 3 of 3 2 NM_000939.4 ENSP00000379170.2 P01189

Frequencies

GnomAD3 genomes
AF:
0.000138
AC:
21
AN:
151886
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.000508
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:
0.0000359
AC:
9
AN:
250566
AF XY:
0.0000295
show subpopulations
Gnomad AFR exome
AF:
0.000494
Gnomad AMR exome
AF:
0.0000289
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:
0.00
GnomAD4 exome
AF:
0.0000198
AC:
29
AN:
1461226
Hom.:
0
Cov.:
32
AF XY:
0.0000124
AC XY:
9
AN XY:
726934
show subpopulations
African (AFR)
AF:
0.000807
AC:
27
AN:
33478
American (AMR)
AF:
0.0000224
AC:
1
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26126
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39696
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86240
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52916
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5764
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111912
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60372
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.461
Heterozygous variant carriers
0
3
6
10
13
16
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:
0.000138
AC:
21
AN:
151886
Hom.:
0
Cov.:
33
AF XY:
0.0000944
AC XY:
7
AN XY:
74170
show subpopulations
African (AFR)
AF:
0.000508
AC:
21
AN:
41340
American (AMR)
AF:
0.00
AC:
0
AN:
15270
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5134
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4810
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10596
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
67954
Other (OTH)
AF:
0.00
AC:
0
AN:
2086
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
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:
0.000166
Hom.:
0
Bravo
AF:
0.000151
ESP6500AA
AF:
0.000681
AC:
3
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.0000330
AC:
4

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: no assertion criteria provided
LINK: link

Submissions by phenotype

POMC-related disorder Uncertain:1
Sep 16, 2024
PreventionGenetics, part of Exact Sciences
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

The POMC c.668T>C variant is predicted to result in the amino acid substitution p.Met223Thr. This variant was reported in the heterozygous state in a patient with severe obesity (Courbage et al. 2021. PubMed ID: 34097736). It was also observed in a cohort of obese individuals, and in vitro functional studies show strong evidence of loss of function (Table 3 and Supplemental Data Set, Shah et al. 2023. PubMed ID: 36864747). This variant is reported in 0.052% of alleles in individuals of African descent in gnomAD. Although we suspect that this variant may be pathogenic, at this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.71
BayesDel_addAF
Benign
-0.067
T
BayesDel_noAF
Uncertain
0.020
CADD
Uncertain
24
DANN
Uncertain
0.99
DEOGEN2
Uncertain
0.52
D;D;D;D;T
Eigen
Uncertain
0.57
Eigen_PC
Uncertain
0.48
FATHMM_MKL
Uncertain
0.96
D
LIST_S2
Uncertain
0.97
D;.;.;.;D
M_CAP
Uncertain
0.089
D
MetaRNN
Uncertain
0.69
D;D;D;D;D
MetaSVM
Uncertain
0.36
D
MutationAssessor
Uncertain
2.7
M;M;M;M;.
PhyloP100
5.5
PrimateAI
Uncertain
0.74
T
PROVEAN
Pathogenic
-5.0
D;D;D;D;D
REVEL
Pathogenic
0.74
Sift
Uncertain
0.0010
D;D;D;D;D
Sift4G
Pathogenic
0.0010
D;D;D;D;.
Polyphen
0.99
D;D;D;D;.
Vest4
0.64
MVP
0.98
MPC
0.47
ClinPred
0.58
D
GERP RS
3.9
Varity_R
0.77
gMVP
0.72
Mutation Taster
=47/53
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: rs150343979; hg19: chr2-25384086; API