Children with ocular motor apraxia type Cogan carry deletions in the gene (NPHP1) for juvenile nephronophthisis

Congenital ocular motor apraxia type Cogan is characterized by impairment o f horizontal voluntary eye movements, ocular attraction movements, and opto kinetic nystagmus. Two patients with congenital ocular motor apraxia type C ogan exhibited a newly recognized association with nephronophthisis type 1, an autosomal recessive kidney disease. Both patients possess large deletio ns of the NPHP1 gene. The deletion occurred on both chromosomes 2q13 in one patient and heterozygously in combination with a point mutation of the NPH P1 gene in the other. The findings will help to elucidate the pathogenetic processes involved.