Ocular coloboma is a rare developmental eye disorder that can result in childhood blindness. Despite numerous genes  being associated with coloboma, many cases are unexplained, suggesting novel genes remain to be discovered. One approach to gene identification is reviewing variants in genes located within known chromosomal deletions associated with structural eye defects. We thus identified predicted loss-of-function variants in MAZ, FOXP1, and SIN3B (involved in 16p11.2, 3p14, and 19p13.11 deletions, respectively) in families with colobomatous microphthalmia, along with two novel cases of 16p11.2 deletions. These findings represent potential phenotypic expansions for FOXP1/SIN3B-related disease and a novel disease association for MAZ. (By Dr. Elena Semina, https://jmg.bmj.com/content/early/2025/12/03/jmg-2025-111125 )