2-25161247-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000939.4(POMC):c.638C>T(p.Ala213Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000211 in 1,611,794 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: 𝑓 0.000046 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000018 (0 hom.)
• Consequence: POMC NM_000939.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 0.321

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.08918223).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
POMC	NM_000939.4	c.638C>T	p.Ala213Val	missense_variant	3/3	ENST00000395826.7
POMC	NM_001035256.3	c.638C>T	p.Ala213Val	missense_variant	4/4
POMC	NM_001319204.2	c.638C>T	p.Ala213Val	missense_variant	4/4
POMC	NM_001319205.2	c.638C>T	p.Ala213Val	missense_variant	3/3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
POMC	ENST00000395826.7	c.638C>T	p.Ala213Val	missense_variant	3/3	2	NM_000939.4	P1

Frequencies

GnomAD3 genomes AF: 0.0000461 AC: 7 AN: 151702 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000242

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000656

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: 0.0000737

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000484 AC: 12 AN: 247882 Hom.: 0 AF XY: 0.0000446 AC XY: 6 AN XY: 134390

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.000204

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000357

Gnomad OTH exome AF: 0.000165

GnomAD4 exome AF: 0.0000185 AC: 27 AN: 1459972 Hom.: 0 Cov.: 32 AF XY: 0.0000220 AC XY: 16 AN XY: 726104

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.000179

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000171

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000461 AC: 7 AN: 151822 Hom.: 0 Cov.: 33 AF XY: 0.0000809 AC XY: 6 AN XY: 74210

Gnomad4 AFR AF: 0.0000242

Gnomad4 AMR AF: 0.0000655

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000737

Gnomad4 OTH AF: 0.00

Bravo AF: 0.0000264

ExAC AF: 0.0000412 AC: 5

Asia WGS AF: 0.000289 AC: 1 AN: 3478

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Obesity Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Apr 27, 2017

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Dec 21, 2023

This sequence change replaces alanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 213 of the POMC protein (p.Ala213Val). This variant is present in population databases (rs757423347, gnomAD 0.02%). This variant has not been reported in the literature in individuals affected with POMC-related conditions. ClinVar contains an entry for this variant (Variation ID: 895579). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt POMC protein function with a negative predictive value of 80%. 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. -

Obesity due to pro-opiomelanocortin deficiency Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Apr 27, 2017

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_addAF	Benign	-0.25	T
BayesDel_noAF	Benign	-0.31
Cadd	Benign	5.9
Dann	Benign	0.94
DEOGEN2	Benign	0.29	T;T;T;T;T
Eigen	Benign	-1.2
Eigen_PC	Benign	-1.3
FATHMM_MKL	Benign	0.20	N
LIST_S2	Benign	0.41	T;.;.;.;T
M_CAP	Benign	0.039	D
MetaRNN	Benign	0.089	T;T;T;T;T
MetaSVM	Benign	-0.93	T
MutationAssessor	Benign	1.3	L;L;L;L;.
MutationTaster	Benign	1.0	N;N;N;N
PrimateAI	Uncertain	0.58	T
PROVEAN	Benign	-0.97	N;N;N;N;N
REVEL	Benign	0.24
Sift	Benign	0.14	T;T;T;T;T
Sift4G	Benign	0.31	T;T;T;T;.
Polyphen		0.083	B;B;B;B;.
Vest4		0.064
MutPred		0.25		Gain of sheet (P = 0.0149);Gain of sheet (P = 0.0149);Gain of sheet (P = 0.0149);Gain of sheet (P = 0.0149);Gain of sheet (P = 0.0149);
MVP		0.72
MPC		0.30
ClinPred		0.028	T
GERP RS		-0.99
Varity_R		0.035
gMVP		0.088

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

Other links and lift over

dbSNP: rs757423347; hg19: chr2-25384116;