SMPD1 and Failure to thrive: The disease is associated with mutations in ASM encoding gene SMPD1, resulting in sphingomyelin accumulation in reticuloendothelial cells and hepatocytes.1 Clinically, NPD patients usually present with enlargement of body organs such as liver and spleen (hepatosplenomegaly), fail to weight gaining and growth in a usual way (failure to thrive), progressive loss of mental abilities, loss of muscle movement, eye abnormality called a cherry-red spot and recurrent lung infections.