8-43103585-GC-G

Variant names:

• chr8-43103585-GC-G
• rs749980792
• NM_032237.5:c.43delC

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1 PM2

The NM_032237.5(POMK):​c.43delC​(p.Arg15GlufsTer11) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000616 in 1,461,870 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. R15R) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000062 (0 hom.)
• Consequence: POMK NM_032237.5 frameshift
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -1.29
• Publications: 0 publications found

Genes affected

POMK (HGNC:26267): (protein O-mannose kinase) This gene encodes a protein that may be involved in the presentation of the laminin-binding O-linked carbohydrate chain of alpha-dystroglycan (a-DG), which forms transmembrane linkages between the extracellular matrix and the exoskeleton. Some pathogens use this O-linked carbohydrate unit for host entry. Loss of function compound heterozygous mutations in this gene were found in a human patient affected by the Walker-Warburg syndrome (WWS) phenotype. Mice lacking this gene contain misplaced neurons (heterotopia) in some regions of the brain, possibly from defects in neuronal migration. Alternative splicing of this gene results in multiple transcript variants. [provided by RefSeq, May 2013]

POMK Gene-Disease associations (from GenCC):

• muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type a, 12

  Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE Submitted by: G2P, Ambry Genetics, Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
• congenital muscular dystrophy with cerebellar involvement

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• limb-girdle muscular dystrophy due to POMK deficiency

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• muscular dystrophy-dystroglycanopathy, type A

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 10 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most 50 bp of the penultimate exon, not predicted to undergo nonsense mediated mRNA decay. There are 27 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_032237.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	POMK	NM_032237.5	MANE Select	c.43delC	p.Arg15GlufsTer11	frameshift	Exon 4 of 5	NP_115613.1	Q9H5K3
	POMK	NM_001277971.2		c.43delC	p.Arg15GlufsTer11	frameshift	Exon 3 of 4	NP_001264900.1	Q9H5K3

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	POMK	ENST00000331373.10	TSL:2 MANE Select	c.43delC	p.Arg15GlufsTer11	frameshift	Exon 4 of 5	ENSP00000331258.5	Q9H5K3
	POMK	ENST00000676193.1		c.43delC	p.Arg15GlufsTer11	frameshift	Exon 3 of 4	ENSP00000502774.1	Q9H5K3
	POMK	ENST00000936358.1		c.43delC	p.Arg15GlufsTer11	frameshift	Exon 4 of 6	ENSP00000606417.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251106 AF XY: 0.00

Gnomad AFR exome AF: 0.00

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: 0.00000882

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000616 AC: 9 AN: 1461870 Hom.: 0 Cov.: 32 AF XY: 0.00000275 AC XY: 2 AN XY: 727246

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

American (AMR) AF: 0.0000447 AC: 2 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: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53398

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

European-Non Finnish (NFE) AF: 0.00000629 AC: 7 AN: 1112010

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

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		-1.3
Mutation Taster		=45/155	disease causing (fs/PTC)

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: rs749980792; hg19: chr8-42958728; COSMIC: COSV58856931;