A genetic mutation associated with childhood glaucoma is reported in the Journal of Clinical Investigation this week. In the study, a team led by scientists from Boston Children's Hospital analyzed whole-exome sequencing data from a family of European ancestry with congenital glaucoma. They identified a heterozygous missense variant in thrombospondin 1 (THBS1), a protein known to be involved in angiogenesis and other biological processes, in those with early-onset disease but not unaffected individuals. In follow-on experiments, the mutation, which alters a highly conserved amino acid, was found among childhood glaucoma sufferers from three unrelated and ethnically diverse families. The researchers then developed a mouse model with the THBS1 mutation, which showed symptoms of glaucoma. They also demonstrated that the mutation leads to misfolding of the THBS1 protein, causing the buildup of extracellular matrix proteins in the structures of the eye involved with regulating intraocular pressure (IOP). This elevated IOP — a hallmark of glaucoma — damages the optic nerve and results in the loss of retinal ganglion cells. "These results further support a role for THBS1 in the regulation of intraocular fluid dynamics and IOP and provide new opportunities for genetic testing and therapeutic intervention," the study's authors write.