A diagnosis of TANGO2-related metabolic encephalopathy and arrhythmias is based upon identification of characteristic symptoms, history, examination, and bloods including genetics. Diagnostic criteria for this disorder have not yet been established.
The latest natural history study aims to show specific characteristics that are often found in affected individuals.
- Affected individuals will develop symptoms in childhood or infancy. This may coincide with feeding changes, illness, growth or increased activity and therefore energy requirements.
- Some children can become very sick in such situations and develop metabolic crisis with rhabdomyolysis and arrhythmia. Other affected children have not had crisis but are picked up later with repeated unusual neurological presentations and associated learning problems.
- TANGO2 spells are often described in patients with repeated episodes of fatigue/ head tilt/ataxic walk/ ptosis and dysphagia. Children or affected adults may be more predisposed to clusters of these episodes which may worsen with growth spurts/ illness/ fatigue or stress.
- TANGO2 affected individuals are known to frequently develop muscle spasticity, hypothyroidism and epilepsy yet it is unclear why.
- Hypothyroidism, palatal issues, learning difficulties and epilepsy are common associated with Tango2 deficiency disorder and should be screened for and considered part of the regular review.
- 3) emergency Protocol- add link for pts to download.
TANGO2 itself is a protein coding gene on chromosome 22 (22q11.21). This gene belongs to the transport and Golgi organization family, whose members are predicted to play roles in secretory protein loading in the endoplasmic reticulum.
What is TANGO2 deficiency disorder?
Also known as TANGO2 disease, TANGO2-related disorder, TANGO2-related deficiency disorder, TANGO2 disease, TANGO2-Related Metabolic Encephalopathy and Arrhythmia.
TANGO2-related disease is a rare genetic disorder caused by changes in the TANGO2 gene. Both genes need to be affected for people to have TANGO2.
It is estimated that 1 in 566 carry a defective TANGO2 gene but due to them having 1 fully functioning gene they are unaffected. TANGO2 deficiency disorder occurs when an individual has 2 genes that do not work.
Affected individuals experience episodes of acute illness called metabolic crises. These episodes can be triggered by illness or from not eating for an extended period of time (fasting) and then they are unable to access typical energy stores effectively.
A range of problems can occur- Irregularities in the rhythm of the heart (arrhythmias), breakdown of muscle tissue (rhabdomyolysis), and brain disease due to accumulation of toxins (encephalopathy).
Additional signs and symptoms can occur both within and outside of metabolic crisis. TANGO2 can affect people very differently. Neurological problems including intellectual disability and delays in reaching developmental milestones can also occur and appears common.
There is no cure for the disorder, but research is underway to better understand and treat this disease. Current treatment is aimed at the specific symptoms present in each individual and optimizing an individual’s access to energy.
How can individuals be diagnosed with TANGO2?
Most affected individuals will present in either crisis or unwell or at a young age with problems walking and talking and developmental delay. There are some distinguishing features to TANGO2 presentation which may help a clinician recognize it such as the unusual gait. However, diagnosis can only be confirmed by genetic testing. Due to its rarity this can take many years before it is identified.
