Heterozygous missense mutations in PITX3 have been reported in patients with autosomal dominant congenital cataract and anterior segment (ocular) mesenchymal dysgenesis (ASMD) whereas homozygous missense mutations have been found in patients with microphthalmia and neurological impairment.
In one family, a novel BFSP2 mutation causes autosomal recessive diffuse cortical cataract with scattered lens opacities, and in another, a novel PITX3 mutation causes an autosomal recessive severe form of anterior segment dysgenesis and microphthalmia.
Human patients with point mutations in PITX3 demonstrate congenital cataracts along with anterior segment defects in some cases when one allele is affected and microphthalmia with brain malformations when both copies are mutated.