[P3-152] Oculomotor apraxia as an initial sign in Joubert syndrome and related disorders with NPHP1 Gene Deletion
We present two cases of Joubert syndrome and related disorders (JSRD), who had symptom of oculomotor apraxia as an initial sign of the disease, with NPHP1 gene deletion that appears to be responsible for juvenile nephronophthisis type 1. Case1 is a twelve-year-old boy, who came to us because of congenital oculomotor apraxia and developmental delay. We found the molar tooth sign (MTS) on brain magnetic resonance imaging (MRI) and diagnosed JSRD. He has no history of breathing abnormalities. His renal function had gradually declined from age of ten years, and we recently identified homozygous deletion of the NPHP1 gene on genetic testing. He progressed to chronic kidney disease stage3, we are following up him with a kidney specialist. Case2 is a three-year-old boy with congenital oculomotor apraxia. Hypotonia was pointed out from birth, but abnormal breathing pattern was not seen. We had found the MTS on brain MRI, he was also diagnosed JSRD. Although he does not show signs of renal failure, we should follow up his renal function diligently on the ground that we identified homozygous deletion of the NPHP1 gene on his genetic testing. We conclude that genetic testing for JSRD can be useful for predicting the progression of renal failure and providing information about individually suited management. (210 words)