Joubert syndrome with variable features: presentation of two cases.

Area of Science:

• Neurology
• Genetics
• Pediatrics

Background:

• Joubert syndrome is a rare ciliopathy characterized by specific brain abnormalities, including cerebellar vermis agenesis and the molar tooth sign.
• Clinical manifestations vary widely, encompassing respiratory irregularities, oculomotor apraxia, hypotonia, and global developmental delay.

Observation:

• Two cases of Joubert syndrome with distinct phenotypes are presented.
• Case 1: An 8-month-old girl with hypotonia, apnea, mild developmental delay, retinal degeneration, and unilateral renal cystic dysplasia.
• Case 2: A 27-month-old boy with hyperpnea, apnea, retinal dystrophy, and severe global developmental delay.

Findings:

• Both patients exhibited classic neuroimaging findings of Joubert syndrome (vermis agenesis, molar tooth sign).
• Metabolic profiles were normal in both cases, ruling out common metabolic disorders.
• Phenotypic variability was evident, with differences in developmental delay severity, retinal involvement, and renal anomalies.

Implications:

• These cases underscore the phenotypic heterogeneity of Joubert syndrome, complicating diagnosis and management.
• Understanding this variability is crucial for accurate prognostication and tailored clinical care.
• Further research into genotype-phenotype correlations may elucidate the underlying mechanisms driving diverse presentations.