1-171635988-C-T

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 2P and 3B. PM2 BP4_Moderate BP7

The NM_000261.2(MYOC):c.1452G>A(p.Lys484=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000131 in 152,184 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★★).

• Frequency: Genomes: 𝑓 0.000013 (0 hom., cov: 32)
• Consequence: MYOC NM_000261.2 synonymous
• Clinical Significance: Uncertain significance reviewed by expert panel U:1
• Conservation: PhyloP100: 1.16

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 Likely_benign. Variant got -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.39).
• BP7: Synonymous conserved (PhyloP=1.16 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MYOC	NM_000261.2	c.1452G>A	p.Lys484=	synonymous_variant	3/3	ENST00000037502.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MYOC	ENST00000037502.11	c.1452G>A	p.Lys484=	synonymous_variant	3/3	1	NM_000261.2	P1
MYOCOS	ENST00000637303.1	c.235-2642C>T		intron_variant		5		A2
MYOC	ENST00000638471.1	c.*790G>A		3_prime_UTR_variant, NMD_transcript_variant	4/4	5

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152184 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000482

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

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: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 31

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152184 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74358

Gnomad4 AFR AF: 0.0000482

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: reviewed by expert panel

Submissions by phenotype

Glaucoma of childhood Uncertain:1

Uncertain significance, reviewed by expert panel

curation

ClinGen Glaucoma Variant Curation Expert Panel

Feb 15, 2023

The c.1452G>A variant in MYOC is a synonymous variant (p.Lys484=). The gnomAD (v2.1.1) database had poor genotype data for this genomic position and did not represent the population from which the variant has been reported (South Asian). Thus PM2_Supporting was not applied to this variant. Although this synonymous variant was not predicted to affect splicing, as assessed with SpliceAI (<=0.2), it had a CADD score (v1.6) = 10.90, which did not meet the <=10 threshold for BP4 and a GERP score = 4.88 (threshold <0), not meeting BP7 and indicating conservation at this site. There was no functional evidence predicting a damaging or benign impact of this variant on MYOC function. Although probands with JOAG have been reported carrying this variant, PM2_Supporting was not met, therefore PS4 did not apply. In summary, this variant did not meet any criteria, receiving a score of 0 and a classification as a variant of uncertain significance (uncertain significance classification range -1 to 5) for juvenile open angle glaucoma based on the ACMG/AMP criteria met, as specified by the ClinGen Glaucoma VCEP (v1, 12 Oct 2021): none -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.39
Cadd	Benign	12
Dann	Benign	0.66

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: rs1378048690; hg19: chr1-171605128; COSMIC: COSV50681232;