A case of ‘Joubert Syndrome 31’ due to CEP120 homozygous mutation

Joubert syndrome is a rare autosomal recessive disease characterized by partial or complete absence of the cerebellar vermis. Three main clinical features are; congenital hypotonia, growth retardation and molar tooth findings detected on cranial magnetic resonance imaging. Episodic apnea-tachypnea attacks, abnormal eye movements and ataxia can be seen. Apart from the neurological system, other system findings often accompany the disease. Retinal, liver, kidney and skeletal system involvements can be seen. To date, 34 genes associated with Joubert syndrome have been reported. Many of these genes encode ciliary proteins or regulatory proteins involved in their function. Joubert Syndrome 31. Cranial magnetic resonance imaging revealed a molar tooth sign in 7 month-aged girl who has congenital hypotonia and whose parents were consanguineous. The c.855A>G homozygous mutation in the CEP120 gene was determined in whole exome sequencing and the patient was diagnosed with Joubert syndrome 31. Since Joubert syndrome is a ciliary dyskinesia, multisystemic involvement can be expected in the course of the disease. However, only pure neurological involvement has been reported in the literature in cases of Joubert Syndrome associated with the CEP120 gene. In our patient, multisystemic involvement was not observed in the 2-year follow-up, which is consistent with the literature.
Keywords: Joubert, congenital hypotonia, growth retardation, molar tooth sign, CEP120 gene