rs8192605

Variant names:

• chr2-25164755-G-A
• rs8192605
• NM_000939.4:c.18C>T

Variant summary

Our verdict is Benign. The variant received -14 ACMG points: 0P and 14B. BP4_Strong BP6 BP7 BS1 BS2

The NM_000939.4(POMC):​c.18C>T​(p.Cys6Cys) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00721 in 1,614,006 control chromosomes in the GnomAD database, including 59 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.0055 (7 hom., cov: 33)
  • Exomes 𝑓: 0.0074 (52 hom.)
• Consequence: POMC NM_000939.4 synonymous
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:4
• Conservation: PhyloP100: 0.712
• Publications: 5 publications found

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

ACMG classification

Our verdict: Benign. The variant received -14 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.83).
• BP6: Variant 2-25164755-G-A is Benign according to our data. Variant chr2-25164755-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 335358.
• BP7: Synonymous conserved (PhyloP=0.712 with no splicing effect.
• BS1: Variant frequency is greater than expected in population amr. GnomAd4 allele frequency = 0.00548 (835/152360) while in subpopulation AMR AF = 0.00863 (132/15302). AF 95% confidence interval is 0.00743. There are 7 homozygotes in GnomAd4. There are 391 alleles in the male GnomAd4 subpopulation. Median coverage is 33. This position passed quality control check.
• BS2: High Homozygotes in GnomAd4 at 7 AR,SD,AD gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
POMC	NM_000939.4	c.18C>T	p.Cys6Cys	synonymous_variant	Exon 2 of 3	ENST00000395826.7	NP_000930.1
POMC	NM_001035256.3	c.18C>T	p.Cys6Cys	synonymous_variant	Exon 3 of 4		NP_001030333.1
POMC	NM_001319204.2	c.18C>T	p.Cys6Cys	synonymous_variant	Exon 3 of 4		NP_001306133.1
POMC	NM_001319205.2	c.18C>T	p.Cys6Cys	synonymous_variant	Exon 2 of 3		NP_001306134.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
POMC	ENST00000395826.7	c.18C>T	p.Cys6Cys	synonymous_variant	Exon 2 of 3	2	NM_000939.4	ENSP00000379170.2

Frequencies

GnomAD3 genomes AF: 0.00548 AC: 835 AN: 152242 Hom.: 7 Cov.: 33

Gnomad AFR AF: 0.00140

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00857

Gnomad ASJ AF: 0.0124

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000207

Gnomad FIN AF: 0.00443

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00780

Gnomad OTH AF: 0.0115

GnomAD2 exomes AF: 0.00582 AC: 1460 AN: 251032 AF XY: 0.00583

Gnomad AFR exome AF: 0.00142

Gnomad AMR exome AF: 0.00737

Gnomad ASJ exome AF: 0.0135

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00531

Gnomad NFE exome AF: 0.00771

Gnomad OTH exome AF: 0.00881

GnomAD4 exome AF: 0.00739 AC: 10799 AN: 1461646 Hom.: 52 Cov.: 31 AF XY: 0.00729 AC XY: 5303 AN XY: 727140

African (AFR) AF: 0.00143 AC: 48 AN: 33472

American (AMR) AF: 0.00751 AC: 336 AN: 44712

Ashkenazi Jewish (ASJ) AF: 0.0127 AC: 332 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.0000464 AC: 4 AN: 86254

European-Finnish (FIN) AF: 0.00480 AC: 256 AN: 53382

Middle Eastern (MID) AF: 0.00124 AC: 7 AN: 5624

European-Non Finnish (NFE) AF: 0.00843 AC: 9373 AN: 1111996

Other (OTH) AF: 0.00734 AC: 443 AN: 60372

GnomAD4 genome AF: 0.00548 AC: 835 AN: 152360 Hom.: 7 Cov.: 33 AF XY: 0.00525 AC XY: 391 AN XY: 74504

African (AFR) AF: 0.00139 AC: 58 AN: 41588

American (AMR) AF: 0.00863 AC: 132 AN: 15302

Ashkenazi Jewish (ASJ) AF: 0.0124 AC: 43 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5188

South Asian (SAS) AF: 0.000207 AC: 1 AN: 4826

European-Finnish (FIN) AF: 0.00443 AC: 47 AN: 10618

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.00779 AC: 530 AN: 68044

Other (OTH) AF: 0.0113 AC: 24 AN: 2116

Alfa AF: 0.00690 Hom.: 2

Bravo AF: 0.00582

Asia WGS AF: 0.000577 AC: 2 AN: 3478

EpiCase AF: 0.00872

EpiControl AF: 0.00699

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:4

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Benign:2

Feb 03, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Sep 01, 2024

CeGaT Center for Human Genetics Tuebingen

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

POMC: BP4, BP7, BS2 -

Obesity Uncertain:1

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

not specified Benign:1

May 09, 2022

Genetic Services Laboratory, University of Chicago

Significance: Benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Obesity due to pro-opiomelanocortin deficiency Benign:1

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.83
CADD	Benign	9.7
DANN	Benign	0.45
PhyloP100		0.71
Mutation Taster		=100/0	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs8192605; hg19: chr2-25387624;