Joubert syndrome: incidence and clinicoradiological description of a genotyped series of seven cases

Abstract

Joubert syndrome is produced by an alteration of the ciliary proteins essential for the structure and function of neurons and organs such as the kidneys, liver, sight, and hearing. Some 34 mutations are currently known. Calculate the incidence / prevalence, describe the phenotype / genotype and radiological alterations of this ciliopathy in our health area. We reviewed the medical records with a diagnosis of Joubert Syndrome in the last 10 years to collect phenotype, radiological characteristics, and extra-neurological manifestations in relation to the genetic alteration detected. 7 cases were included: 5 children (6 -17 years). They had 6 different mutations. Hypotonia, thin / long fingers and delayed psychomotor development were constant. They presented dysmorphic features, mental retardation, ocular apraxia, and nystagmus indistinctly in 3/7; Neonatal apnea/hyperpnea 2/7; hypoplasia of vermis 7/7; Molar syndrome was evident in 6/7 and in 2/7 there was elongation-thinning of cerebellar peduncles. Pontomesencephalic junction tightness 6/7; fastigium of the IV ventricle high in 4/7. Among the somatic complications, retinopathy 2/7, retinal coloboma 1/7, liver fibrosis 1/7, nephronoptysis 1/7 and renal cyst 1/7. The incidence of Joubert syndrome was at least 1 / 20,000 newborns / year. The pontomesencephalic and peduncular radiological alterations were constant. Hypotonia, psychomotor retardation, and thin / long fingers affected all cases.