Dominant variants in PRR12 result in unilateral or bilateral complex microphthalmia.

TitleDominant variants in PRR12 result in unilateral or bilateral complex microphthalmia.
Publication TypeJournal Article
Year of Publication2021
AuthorsReis, LM, Costakos, D, Wheeler, PG, Bardakjian, T, Schneider, A, Fung, SSM, Semina, EV
Corporate AuthorsUniversity of Washington Center for Mendelian Genomics
JournalClin Genet
Date Published2021 Mar

Complex microphthalmia is characterized by small eyes with additional abnormalities that may include anterior segment dysgenesis. While many genes are known, a genetic cause is identified in only 4-30% of microphthalmia, with the lowest rate in unilateral cases. We identified four novel pathogenic loss-of-function alleles in PRR12 in families affected by complex microphthalmia and/or Peters anomaly, including two de novo, the first dominantly transmitted allele, as well as the first splicing variant. The ocular phenotypes were isolated with no additional systemic features observed in two unrelated families. Remarkably, ocular phenotypes were asymmetric in all individuals and unilateral (with structurally normal contralateral eye) in three. There are only three previously reported PRR12 variants identified in probands with intellectual disability, neuropsychiatric disorders, and iris anomalies. While some overlap with previously reported cases is seen, nonsyndromic developmental ocular anomalies are a novel phenotype for this gene. Additional phenotypic expansions included short stature and normal development/cognition, each noted in two individuals in this cohort, as well as absence of neuropsychiatric disorders in all. This study identifies new associations for PRR12 disruption in humans and presents a genetic diagnosis resulting in unilateral ocular phenotypes in a significant proportion of cases.

Alternate JournalClin Genet
PubMed ID33314030
Grant ListN/A / / Children's Research Institute Foundation at Children's Wisconsin /
R01EY025718 / EY / NEI NIH HHS / United States
1UL1RR031973 / RR / NCRR NIH HHS / United States
UM1 HG006493 / HG / NHGRI NIH HHS / United States
R21HD099701 / / National Institute of Child Health and Human Development /
U24 HG008956 / HL / NHLBI NIH HHS / United States