chr18-60371389-GA-G

Variant names:

• chr18-60371389-GA-G
• rs13447340
• NM_005912.3:c.960delT

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PVS1_Moderate PM2

The NM_005912.3(MC4R):​c.960delT​(p.Leu322TrpfsTer33) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,868 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: MC4R NM_005912.3 frameshift
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.292
• Publications: 0 publications found

Genes affected

MC4R (HGNC:6932): (melanocortin 4 receptor) The protein encoded by this gene is a membrane-bound receptor and member of the melanocortin receptor family. The encoded protein interacts with adrenocorticotropic and MSH hormones and is mediated by G proteins. This is an intronless gene. Defects in this gene are a cause of autosomal dominant obesity. [provided by RefSeq, Jan 2010]

MC4R Gene-Disease associations (from GenCC):

• inherited obesity

  Inheritance: AD Classification: STRONG Submitted by: Laboratory for Molecular Medicine
• obesity due to melanocortin 4 receptor deficiency

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ENSG00000285681 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.039 CDS is truncated, and there are 0 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_005912.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MC4R	NM_005912.3	MANE Select	c.960delT	p.Leu322TrpfsTer33	frameshift	Exon 1 of 1	NP_005903.2

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MC4R	ENST00000299766.5	TSL:6 MANE Select	c.960delT	p.Leu322TrpfsTer33	frameshift	Exon 1 of 1	ENSP00000299766.3
	ENSG00000285681	ENST00000650201.1		n.113+42045delA		intron	N/A
	ENSG00000285681	ENST00000658928.1		n.156+42045delA		intron	N/A

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461868 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727240

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

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: 53414

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111994

Other (OTH) AF: 0.00 AC: 0 AN: 60396

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		-0.29
Mutation Taster		=27/173	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

Other links and lift over

dbSNP: rs13447340; hg19: chr18-58038622;