Andermann syndrome

Andermann Syndrome is known by several other names including:

• Charlevoix disease
• Agenesis of corpus callosum with neuronopathy
• Agenesis of the corpus callosum with peripheral neuropathy; ACCPN
• Polyneuropathy, sensorimotor, with or without agenesis of the corpus callosum
• Hereditary motor and sensory neuropathy with agenesis of the corpus callosum
• HMSN/ACC

Andermann Syndrome is most common in French Canadian populations in a northwestern region of Quebec. In this area, the condition occurs in approximately 1 in 2,000 births. Andermann Syndrome is rarely seen in other areas of the world. In 2019 there was a case reported in a Roma individual in Bulgaria suggesting that Andermann Syndrome may be more common in this population. However, further studies are required to confirm this.

The common abbreviation for Andermann Syndrome is ACCPN.

Individuals with Andermann syndrome have abnormal or absent reflexes and weak muscle tone. They may experience muscle wasting with progressive weakness, loss of feeling in their arms and legs, and have rhythmic shaking (tremors). Individuals learn to walk, often late, between ages 3 and 4, but lose this ability by adolescence. If the cranial nerves are impacted, the facial muscles may be weak. Eyelids may droop (ptosis) and eyes may not track objects well. Joint contractures occur as affected individuals get older. Many develop curvature of the spine (scoliosis), which may require surgery to correct.

Other physical features may include widely spaced eyes (hypertelorism); a short skull (brachycephaly); a higher than normal hard palate in the mouth; a big toe that crosses over the other toes; and partially fused second and third toes (syndactyly).

Individuals usually have intellectual disabilities, which range from mild to severe. Some experience seizures.

In their 20's, many people with Andermann Syndrome will develop psychiatric manifestations such as hallucinations, depression, delusions, or “autistic-like” behavior that should be evaluated by a psychiatrist.