Additionally, NS/LS zebrafish models have been used to investigate the role of PTPN11 mutations in both congenital sensorineural hearing loss and heart defects which are found in individuals with NS and LS (Sarkozy et al., 2008; Bonetti et al., 2014a; Gao et al., 2020). The gene discussed is PTPN11; the disease is Leigh syndrome.