The severe male X-linked recessive microphthalmia syndrome ('Lenz') usually includes developmental delay in addition to the eye findings and is caused by hypomorphic BCOR variants, mainly by a specific missense variant c.254C > T, p.(Pro85Leu).
In contrast to the previously published families, our findings demonstrate a large variability of BCOR-associated, syndromic phenotypes, indicating incomplete penetrance of p.Pro85Leu with regards to microphthalmia in males.
We have sequenced a cohort of males diagnosed with putative X-linked microphthalmia and found a mutation, p.P85L, in a single case, suggesting that BCOR mutations are not a major cause of X-linked microphthalmia in males.