Ventricular arrhythmia and Noonan syndrome with leucine zipperlike transcription regulator 1 mutations: expanding the phenotype with a case report and review of the literature.

BACKGROUND: Noonan syndrome is characterised by typical facial features, short stature, CHDs, and other comorbidities, which are caused by germline mutations in genes coding for components of the Ras-mitogen-activated protein kinase pathway. Noonan syndrome is an inherited disease involving multiple systems, but ventricular arrhythmia in Noonan syndrome is rarely reported.

CASE SUMMARY: Here we report a 15-year-old patient with leucine zipperlike transcription regulator 1-associated Noonan syndrome, who has CHD (left ventricular hypertrophy with left ventricular outflow tract obstruction), ventricular arrhythmia, bundle branch block, pectus excavatum, costal eversion, scoliosis, myopia, growth retardation, hearing loss, chest tightness, and fatigue. Chest tightness and fatigue are the main reasons for admission of the patient. The patient was treated with spironolactone, empagliflozin, tolasemide, potassium chloride, and bisoprolol. One month after treatment, the patient has no more chest tightness or fatigue. Genetic testing revealed that the patient had a novel heterozygous variant c.313delT (p.trp105Glyfs * 42) mutation in the leucine zipperlike transcription regulator 1. We provide a review of the literature of leucine zipperlike transcription regulator 1 mutations and find that ventricular arrhythmias have been reported in leucine zipperlike transcription regulator 1-related Noonan syndrome.

DISCUSSION: Our findings expand on the Noonan syndrome phenotype and suggest that mutations in the leucine zipperlike transcription regulator 1 gene are involved in ventricular arrhythmia.