SNP Shot: Genomic Insights

Hereditary sensory and autonomic neuropathy type IE (HSAN IE) is a neurological condition impacting the nervous system. Its hallmark characteristics include sensorineural hearing loss, progressive cognitive decline (dementia), and worsening peripheral neuropathy, specifically affecting the feet and legs.

Individuals with HSAN IE experience hearing loss due to inner ear abnormalities. This hearing loss, impacting both ears, gradually worsens, often resulting in moderate to severe deafness between the ages of 20 and 35.

Dementia typically manifests in affected individuals in their thirties. Prior to noticeable cognitive impairment, some individuals with HSAN IE may exhibit personality changes, such as increased irritability, lack of motivation (apathy), or diminished impulse control.

The peripheral neuropathy associated with HSAN IE stems from impaired function of sensory neurons, which are responsible for transmitting sensory information like pain, temperature, and touch. The progressive loss of sensation in the feet and legs, usually starting in adolescence or early adulthood, can lead to difficulties with ambulation. Due to decreased sensation, individuals may be unaware of foot injuries, predisposing them to open sores, infections, and, in severe cases, potential amputation of the affected areas.

Epilepsy (recurrent seizures) and sleep disturbances can also occur in some individuals with HSAN IE. The severity of symptoms and the age at which they appear can vary significantly, even among family members affected by the condition.

Inheritance:

HSAN IE follows an autosomal dominant inheritance pattern. This means that having only one copy of the mutated gene in each cell is enough to cause the disorder. Most often, an affected individual inherits the mutation from a parent who also has the condition. However, HSAN IE can also arise from new gene mutations in individuals with no family history of the disorder.