chr1-171635974-C-T

Variant names:

• chr1-171635974-C-T
• NM_000261.2:c.1466G>A

Variant summary

Our verdict is Uncertain significance. The variant received 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
• Publications: 0 publications found

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

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: For more information check the summary or visit ClinGen Evidence Repository.
• PM4: For more information check the summary or visit ClinGen Evidence Repository.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000261.2. 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
	MYOC	NM_000261.2	MANE Select	c.1466G>A	p.Trp489*	stop_gained	Exon 3 of 3	NP_000252.1	Q99972

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MYOC	ENST00000037502.11	TSL:1 MANE Select	c.1466G>A	p.Trp489*	stop_gained	Exon 3 of 3	ENSP00000037502.5	Q99972
	MYOC	ENST00000971579.1		c.1571G>A	p.Trp524*	stop_gained	Exon 3 of 3	ENSP00000641638.1
	MYOC	ENST00000877923.1		c.1532G>A	p.Trp511*	stop_gained	Exon 4 of 4	ENSP00000547982.1

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

⚠️ 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: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

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

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1112008

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

ClinVar submissions

Significance: Uncertain significance

Revision: reviewed by expert panel

Pathogenic	VUS	Benign	Condition
-	1	-	Open-angle glaucoma (1)

Computational scores

Source: dbNSFP v4.9

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
PhyloP100		7.9
Vest4		0.90
GERP RS		4.9
Mutation Taster		=9/191	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

hg19: chr1-171605114;