BabyScreen+ newborn screening

Gene: TANGO2

Green List (high evidence)

Folate may assist with TANGO2
DOI: https://doi.org/10.21203/rs.3.rs-1778084/v1

PMID: 35568137

While chronic symptoms are predominantly neurodevelopmental, metabolic stressors such as fasting, dehydration, illness, and excessive heat can trigger episodic metabolic crises characterized by encephalopathy, ataxia, muscle weakness, rhabdomyolysis, and hypoglycemia. During these events, patients can develop acute life-threatening cardiac arrhythmias. Arrhythmias typically initiate with isolated premature ventricular contractions (PVC) followed by recalcitrant ventricular tachycardia. Because these lethal arrhythmias usually do not respond to standard antiarrhythmic therapies, cardiac arrhythmias are the leading cause of death in TDD

Fasting and feeding recommendations to reduce crises and improve cardiac status and neurodev outcomes, reduce risk of cardiac arrhythmias and SCDY

Natural history study (ClinicalTrials.gov Identifier: NCT05374616) strongly suggests that subjects on a multivitamin or a Bcomplex vitamin supplement have a greatly reduced risk for metabolic crises and cardiac arrhythmias

Twenty-seven children were admitted for 43 cardiac crises (median age 6.4 years; interquartile range [IQR] 2.4–9.8 years) at 14 centers. During crisis, QTc prolongation occurred in all (median 547 ms; IQR 504–600 ms) and a type I Brugada pattern in 8 (26%). Arrhythmias included VT in 21 (78%), supraventricular tachycardia in 3 (11%), and heart block in 1 (4%). Nineteen patients (70%) developed cardiomyopathy, and 20 (74%) experienced a cardiac arrest. There were 10 deaths (37%), 6 related to arrhythmias. In 5 patients, recalcitrant VT occurred despite use of antiarrhythmic drugs. In 6 patients, arrhythmias were controlled after extracorporeal membrane oxygenation (ECMO) support; 5 of these patients survived. Among 10 patients who survived VT without ECMO, successful treatment included intravenous magnesium, isoproterenol, and atrial pacing in multiple cases and verapamil in 1 patient. Initiation of feeds seemed to decrease VT events.

Specific diet and fasting plans are recommended for all patients from the neonatal period
Sources: Expert Review

Created: 15 Feb 2023, 4:38 a.m. | Last Modified: 15 Feb 2023, 4:42 a.m.

Panel Version: 0.1865

Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal

Phenotypes
Cardiomyopathy; Metabolic Crises; Arrhythmia; Neurodevelopmental