What is infantile neuroaxonal dystrophy (INAD)?
Infantile neuroaxonal dystrophy (INAD) is a rare, inherited disorder of the body's nervous system. It affects axons, the part of a neuron (nerve cell) that carries messages from the brain to other parts of the body. INAD causes loss of vision, muscular control, and mental skills. These symptoms get worse as time passes.
Certain facial deformities may be present at birth. These could include:
- Prominent forehead
- Crossed eyes
- Unusually small nose or jaw
- Large, low-set ears
For their first few years, a baby with INAD will be alert and responsive, but will become more physically impaired as time passes. Generally, a baby's development starts to slow down between the ages of six months to three years. Symptoms usually start in the first two years of life. Rapid, wobbly eye movements and squints may be the first symptoms. Any of the following can happen next:
- Floppiness in the head, body, and legs (more than in the arms)
- Loss of the ability to sit, crawl, or walk
- Decreased ability to see and speak
Eventually, because of the loss of vision, speech, and mental skills, the child will lose touch with his or her surroundings.
INAD is a progressive disease. In other words, once symptoms begin, they will get worse over time.
Who is more likely to get infantile neuroaxonal dystrophy?
INAD is an autosomal recessive disorder. That means that both parents must be carriers of the defective gene that causes INAD to pass it on to their child.
While the basic genetic and metabolic causes are unknown, INAD is the result of an abnormal build-up of toxic substances in nerves that communicate with muscles, skin, and the conjunctive tissue around the eyes. Mutations in the PLA2G6 gene have been identified in most children with INAD.
How is infantile neuroaxonal dystrophy diagnosed and treated?
Electrophysiology (nerve conduction velocities) may be helpful for diagnosis. Tissue biopsy of skin, rectum, nerve or conjunctive tissue may be used to confirm the presence of characteristic swellings (spheroid bodies) in the nerve axons.
There is no cure for INAD and there is no treatment that can stop the disease from getting worse. Treatment is symptomatic and may include medications to reduce pain and to sedate (help the child stay calm). Physiotherapists and physical therapists can teach parents and caregivers how to position and seat their child and exercise the child's arms and legs to help him or her stay comfortable.
How can I or my loved one help improve care for people with infantile neuroaxonal dystrophy?
Consider participating in a clinical trial so clinicians and scientists can learn more about the INAD and related disorders. Clinical research uses human volunteers to help researchers learn more about a disorder and perhaps find better ways to safely detect, treat, or prevent disease.
All types of volunteers are needed—those who are healthy or may have an illness or disease—of all different ages, sexes, races, and ethnicities to ensure that study results apply to as many people as possible, and that treatments will be safe and effective for everyone who will use them.
For information about participating in clinical research visit NIH Clinical Research Trials and You. Learn about clinical trials currently looking for people with INAD at Clinicaltrials.gov.
Where can I find more information about infantile neuroaxonal dystrophy?
The following organizations may provide more information and resources:
INADcure Foundation (Infantile Neuroaxonal Dystrophy)
NBIA Disorders Association