what is shones complex in a baby
From Wikipedia, the free encyclopedia. Shone's syndrome (also called Shone's Complex, Shone's Anomaly and Shone's Syndrome)is a rare congenital heart disease described by Shone in 1963. In the complete form, four left-sided defects are present:1  Supravalvular mitral membrane (SVMM).s discussed earlier, Shoneâs syndrome is a rare disorder that is often detected in very young children. The children tend to show symptoms like fatigue, nocturnal cough, and reduced cardiac output by the age of two years.