An 8-year-old boy is evaluated for fatigue. Auscultation reveals a holosystolic murmur best heard at the lower sternal border. Echocardiography reveals apical displacement of the tricuspid valve leaflets, decreased right ventricular volume and atrialisation of the right ventricle. Moderate to severe TR is present. This patient's condition is believed to be a teratogenic effect of a drug taken during pregnancy. Which one of the following could not have been the side effect of that drug on biological mother of this patient: -

The child is suffering from Ebstein's anomaly which is characteristically associated with use of lithium during pregnancy. Lithium is a mood stabilizer agent which is used in the treatment of bipolar disorder. Lithium has a very narrow therapeutic index and its side effects include Tremors and other neuropsychiatric complications Hypothyroidism Nephrogenic Diabetes insipidus Acute renal failure Electrolyte imbalances Arrhythmia if toxicity occurs Teratogenicity Acneiform eruptions and Leukocytosis is also a side effect of Lithium therapy which appears to result directly from increased leukopoiesis. However, this is now therapeutically being used in the treatment of patients with low leukocyte counts.