Acute motor axonal neuropathy (AMAN) is a variant of Guillain–Barré syndrome. It is characterized by acute paralysis and loss of reflexes without sensory loss. Pathologically, there is motor axonal degeneration with antibody-mediated attacks of motor nerves and nodes of Ranvier. Signs and symptoms
Causes
A link to Campylobacter jejuni was suspected when a young girl was admitted to Second Teaching Hospital. She had become ill after feeding the family chickens. She developed acute paralysis and respiratory failure. Investigators discovered that several of the chickens in the home displayed similar symptoms and C. jejuni was found in their droppings. Several of the paralysis patients were found to have antibodies to C. jejuni and anti-GD1a antibodies, suggesting a link between the pathogen and the disease. In 2015, Zika virus was linked to AMAN. Diagnosis
The syndrome typically presents as a progressive flaccid symmetric paralysis with areflexia, often causing respiratory failure. Electromyographic studies and nerve conduction studies show normal motor conduction velocity and latency with decreased amplitude of compound muscle action potentials. Pathologically, it is a noninflammatory axonopathy without demyelination. Antibodies attack the coating of the motor neurons without causing inflammation or loss of myelin. It does not affect sensory neurons, so sensation remains intact despite loss of movement. Treatment
the majority of patients have complete symptom resolution with 5-day intravenous immunoglobulin (IV Ig) treatment. Patients with AMAN continue to see improvements in ambulation and functional ability up to four years post-diagnosis.
The breakpoints for 1p36 deletion syndrome have been variable and are most commonly found from 1p36.13 to 1p36.33. 40 percent of all breakpoints occur 3 to 5 million base pairs from the telomere. The size of the deletion ranges from approximately 1.5 million base pairs to greater than 10 million.Most deletions in chromosome 1p36 are de novo mutations. 20% of patients with 1p36 deletion syndrome inherit the disease from one parent who carries a balanced or symmetrical translocation. Diagnosis
1p36 deletion syndrome is usually suspected based on the signs and symptoms and confirmed by fluorescence in situ hybridization (FISH). Chromosomal microarray or karyotype analysis may also be used to diagnose 1p36 deletion. Treatment
There is no cure for 1p36 deletion syndrome, and treatment is focused on relieving symptoms of the disease. Of particular importance are appropriate medication for endocrine and neurologic manifestations, such as anti-seizure medications. Feeding difficulties can be managed with specialized assistive devices or with a gastrostomy (feeding) tube. Epidemiology
1p36 deletion syndrome is the most common terminal deletion syndrome in humans. It occurs in between 1 in 5000 and 1 in 10000 live births. And only 100 cases have been reported since 1981. == References ==