1-171635974-C-T

Position:

• chr1-171635974-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2_Supporting PM4_Supporting

This summary comes from the ClinGen Evidence Repository: The c.1466G>A variant in MYOC is predicted to cause a change in the length of the protein due to the insertion of a terminating codon instead of the usual Tryptophan at amino acid 489. This variant is predicted to cause a deletion of < 10% of the protein within the conserved olfactomedin domain, meeting PM4_Supporting. This variant was not found in any population of gnomAD (v2.1.1), meeting the ≤ 0.0001 threshold set for PM2_Supporting in a population of at least 10,000 alleles. There was no computational or functional evidence predicting a damaging or benign impact of this variant on MYOC function. Only 1 segregation had been reported for primary open angle glaucoma (POAG, A Hewitt, pers. comm.), not meeting the ≥ 3 segregations required for PP1. Only 1 proband with POAG had been reported (A Hewitt pers. comm.), not meeting the ≥ 2 probands threshold required to meet PS4_Supporting. In summary, this variant met the criteria to receive a score of 2 and to be classified as a variant of uncertain significance (uncertain significance classification range -1 to 5) for primary open angle glaucoma based on the ACMG/AMP criteria met, as specified by the ClinGen Glaucoma VCEP (v1, 12 Oct 2021): PM2_Supporting, PM4_Supporting LINK:https://erepo.genome.network/evrepo/ui/classification/CA343723002/MONDO:0007665/019

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: MYOC NM_000261.2 stop_gained
• Clinical Significance: Uncertain significance reviewed by expert panel U:1
• Conservation: PhyloP100: 7.86

Genes affected

MYOC (HGNC:7610): (myocilin) MYOC encodes the protein myocilin, which is believed to have a role in cytoskeletal function. MYOC is expressed in many occular tissues, including the trabecular meshwork, and was revealed to be the trabecular meshwork glucocorticoid-inducible response protein (TIGR). The trabecular meshwork is a specialized eye tissue essential in regulating intraocular pressure, and mutations in MYOC have been identified as the cause of hereditary juvenile-onset open-angle glaucoma. [provided by RefSeq, Jul 2008]

MYOCOS (HGNC:53429): (myocilin opposite strand)

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MYOC	NM_000261.2	c.1466G>A	p.Trp489Ter	stop_gained	3/3	ENST00000037502.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MYOC	ENST00000037502.11	c.1466G>A	p.Trp489Ter	stop_gained	3/3	1	NM_000261.2	P1
MYOCOS	ENST00000637303.1	c.235-2656C>T		intron_variant		5		A2
MYOC	ENST00000638471.1	c.*804G>A		3_prime_UTR_variant, NMD_transcript_variant	4/4	5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461890 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727244

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

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: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: reviewed by expert panel

Submissions by phenotype

Open-angle glaucoma Uncertain:1

Uncertain significance, reviewed by expert panel

curation

ClinGen Glaucoma Variant Curation Expert Panel

May 31, 2023

The c.1466G>A variant in MYOC is predicted to cause a change in the length of the protein due to the insertion of a terminating codon instead of the usual Tryptophan at amino acid 489. This variant is predicted to cause a deletion of < 10% of the protein within the conserved olfactomedin domain, meeting PM4_Supporting. This variant was not found in any population of gnomAD (v2.1.1), meeting the <= 0.0001 threshold set for PM2_Supporting in a population of at least 10,000 alleles. There was no computational or functional evidence predicting a damaging or benign impact of this variant on MYOC function. Only 1 segregation had been reported for primary open angle glaucoma (POAG, A Hewitt, pers. comm.), not meeting the >= 3 segregations required for PP1. Only 1 proband with POAG had been reported (A Hewitt pers. comm.), not meeting the >= 2 probands threshold required to meet PS4_Supporting. In summary, this variant met the criteria to receive a score of 2 and to be classified as a variant of uncertain significance (uncertain significance classification range -1 to 5) for primary open angle glaucoma based on the ACMG/AMP criteria met, as specified by the ClinGen Glaucoma VCEP (v1, 12 Oct 2021): PM2_Supporting, PM4_Supporting -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.58
CADD	Pathogenic	41
DANN	Uncertain	1.0
Eigen	Pathogenic	0.90
Eigen_PC	Pathogenic	0.77
FATHMM_MKL	Uncertain	0.93	D
MutationTaster	Benign	1.0	D
Vest4		0.90
GERP RS		4.9

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr1-171605114;