Ectopia lentis is a genetically heterogeneous condition that is characterized by 
the subluxation of the lens resulting from the disruption of the zonular fibers. 
Patients with ectopia lentis commonly present with a marked loss in visual 
acuity in addition to a number of possibly accompanying ocular complications 
including cataract, myopia, and retinal detachment. We here describe an isolated 
form of ectopia lentis in a large inbred family that shows autosomal-recessive 
inheritance. We map the ectopia lentis locus in this family to the 
pericentromeric region on chromosome 1 (1p13.2-q21.1). The linkage region 
contains well more than 60 genes. Mutation screening of four candidate genes 
revealed a homozygous nonsense mutation in exon 11 of ADAMTSL4 (p.Y595X; 
c.1785T-->G) in all affected individuals that is absent in 380 control 
chromosomes. The mutation would result in a truncated protein of half the 
original length, if the mRNA escapes nonsense-mediated decay. We conclude that 
mutations in ADAMTSL4 are responsible for autosomal-recessive simple ectopia 
lentis and that ADAMTS-like4 plays a role in the development and/or integrity of 
the zonular fibers.