Familial dysautonomia.

Area of Science:

• Genetics
• Neurology
• Molecular Biology

Background:

• Familial dysautonomia (FD), an autosomal recessive hereditary sensory and autonomic neuropathy (HSAN type 3), presents at birth with severe sensory loss and high mortality.
• The founder mutation in the ELP1 gene, originating in Ashkenazi Jews, affects 1 in 30 individuals of European ancestry.
• This mutation causes tissue-specific exon skipping, leading to a loss of function in the essential elongator-1 protein (ELP1) crucial for neuronal development and survival.

Purpose of the Study:

• To investigate the genetic basis and molecular mechanisms of Familial Dysautonomia (FD).
• To understand the clinical manifestations and disease progression in FD patients.
• To explore potential therapeutic strategies and identify reliable endpoints for clinical trials.

Main Methods:

• Analysis of the ELP1 gene mutation and its effect on protein function.
• Clinical assessment of patients with FD, including neurological and physiological evaluations.
• Investigation of phenotypic variability and potential genetic modifiers.

Main Results:

• The FD founder mutation results in a loss of function of the ELP1 protein due to exon 20 skipping.
• Patients exhibit significant clinical variability despite high homozygosity for the founder mutation, suggesting modifier genes.
• Key symptoms include autonomic crises, blood pressure variability, neurogenic dysphagia, progressive vision loss, and ataxia.

Conclusions:

• The ELP1 mutation is the primary cause of FD, impacting neuronal survival and function.
• Phenotypic variability underscores the role of genetic modifiers in FD.
• Disease-modifying therapies are nearing clinical testing, with ELP1 levels serving as a surrogate endpoint for treatment efficacy.