Noonan syndrome due to a SHOC2 mutation presenting with fetal distress and fatal hypertrophic cardiomyopathy in a premature infant.

ABSTRACT

We report on a patient with Noonan syndrome due to SHOC2 missense mutation predicting p.Ser2Gly, recently described in association with Noonan syndrome. The male infant presented with fetal distress requiring premature delivery at 32 weeks and was noted to have dysmorphic features, edema, hepatosplenomegaly, leukocytosis, thrombocytopenia, and respiratory distress following birth. An echocardiogram revealed hypertrophic cardiomyopathy with left ventricular outflow tract obstruction. The infant's cardiac lesion rapidly progressed, and he was discharged home for palliative care. Clinical testing of genes causative of Noonan syndrome and related disorders detected the previously reported, pathogenic, de novo SHOC2 missense mutation predicting p.Ser2Gly. The patient's cardiac findings and features were not typical for those individuals previously reported with this SHOC2 mutation and thus expand the clinical phenotype.