KIF1A

SIGNS AND SYMPTOMS OF THE DISEASE

KAND disease is a neurodegenerative disease, its course looks different in each person. The pace of development and severity of symptoms depends on the type of mutation, with some occurring more frequently than others. The research team from the Chung Laboratory at Boston Children's Hospital has already analyzed over 330 rare available KAND cases to thoroughly understand the clinical picture of this disease.

• Movement:

People living with KAND struggle with many overlapping symptoms, such as muscle weakness, impaired coordination, reflexes, and balance. Over time, these may worsen, both as a result of progressive degeneration and increasing burden on the body as it develops. Spasticity is a common consequence of the disease, which often leads to bone fractures.

• Peripheral neuropathy:

develops as a result of damage to peripheral nerves, which are responsible for transmitting signals from the brain and spinal cord to the entire body. It can manifest as numbness in hands and feet, piercing, burning or tingling pain, excessive sensitivity to touch, as well as problems with motor coordination. People with KAND often have reduced sensitivity to pain and temperature, which increases the risk of overheating or underestimating injuries.

• Vision disorders:

Unfortunately, vision disorders are one of the most common symptoms of KAND, affecting as many as 84% of patients. Typical symptoms include reduced visual acuity, difficulty with depth perception, limited visual field and color recognition disorders. Many patients also show optic nerve atrophy, visual coloboma, as well as strabismus or azotropia. The degree of severity and pace of progression of these problems can vary significantly among individuals.

• Epilepsy:

Almost half of people living with KAND experience seizures, the type and frequency of which can vary greatly. These include absence seizures, tonic-clonic, spasms, atonic and partial seizures - both simple and complex. In a survey study, over 60% of participants reported that seizures appeared in the first year of life. However, in some people with KAND, seizures often occur at night and may remain undetected during routine EEG examination. That is why proper EEG monitoring is so important, which allows for accurate diagnosis and appropriate treatment. Untreated seizures can lead to serious brain damage over time, and in extreme cases even death.

• Developmental and behavioral disorders in KAND:

Intellectual disability in children with KAND is most often associated with delays in speech, language and motor skills development, while mutations in the KIF1A gene can also lead to autism spectrum disorders, manifested by abnormal sensory sensitivity, difficulties in communication and social relationships, and repetitive behaviors; additionally, some patients have ADHD, characterized by problems with concentration, impulsivity and hyperactivity, which can significantly affect daily functioning and quality of life.

• Cerebellar atrophy:

Cerebellar atrophy is a condition resulting from progressive degeneration of the cerebellum - the brain area responsible for motor coordination. It can lead to problems with muscle coordination, loss of balance and unsteady gait, as well as slurred speech, difficulty swallowing or chewing, and in some cases even depression.

https://www.kif1a.org/kand/signs-symptoms/