Joubert syndrome and related disorders

Area of Science:

• Genetics
• Neurology
• Developmental Biology

Background:

• Joubert syndrome (JS) is a rare autosomal recessive condition characterized by a distinctive molar tooth sign (MTS) in the midbrain-hindbrain.
• Neurological symptoms include hypotonia, ataxia, developmental delay, abnormal eye movements, and neonatal breathing issues.
• JS often involves multiorgan conditions like retinal, kidney, and liver issues, collectively termed Joubert syndrome and related disorders (JSRDs), all sharing the MTS.

Purpose of the Study:

• To review the genetic basis of Joubert syndrome and related disorders (JSRDs).
• To highlight the clinical and genetic overlap with other ciliopathies.
• To emphasize the implications of genotype-phenotype correlations for diagnosis and management.

Main Methods:

• Review of identified causative genes for JSRDs.
• Analysis of clinical and genetic data from affected individuals.
• Comparison with other known ciliopathies.

Main Results:

• Sixteen causative genes for JSRDs have been identified, encoding proteins of the primary cilium.
• JSRDs share genetic and clinical features with other ciliopathies, including Meckel syndrome.
• Emerging genotype-phenotype correlations are crucial for diagnosis, follow-up, and management.

Conclusions:

• Understanding the genetic underpinnings of JSRDs is vital for clinical practice.
• Genetic testing enables early prenatal diagnosis for at-risk families.
• Further research into genotype-phenotype correlations will refine patient care.