The c.1021T>C variant in MYOC is a missense variant predicted to cause substitution of Serine by Proline at amino acid 341 (p.Ser341Pro). 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. The REVEL score = 0.821, which met the ≥ 0.7 threshold for PP3, predicting a damaging effect on MYOC function. There was no functional evidence predicting a damaging or benign impact of this variant on MYOC function. 12 segregations in 4 families, with juvenile or primary open angle glaucoma (JOAG or POAG), have been reported (PMIDs: 17867509, 24825108, 33214997, 25777973), which fulfilled PP1_Strong (≥ 7 meioses in >1 family). 8 probands with JOAG or POAG have been reported carrying this variant (PMIDs: 9510647, 24825108, 25777973, 33214997, 17867509, ClinVar: Invitae), which met PS4_Moderate (≥ 6 probands). In summary, this variant met the criteria to receive a score of 8 and to be classified as likely pathogenic (likely pathogenic classification range 6 to 9) for juvenile open angle glaucoma based on the ACMG/AMP criteria met, as specified by the ClinGen Glaucoma VCEP (v1, 12 Oct 2021): PP1_Strong, PP3, PS4_Moderate, PM2_Supporting.