Jillian Arnold | Rare Disease Mama x2 🦓 on Instagram: "Genetic diseases don’t “show up later.” Children with Niemann-Pick Type A/B are born with significantly reduced enzyme activity. At birth, there may still be enough residual function for early development to “look typical.” Over time, sphingomyelin accumulates in the brain and nervous system. As that buildup reaches toxic levels, neurons are damaged and previously acquired skills can be lost. That delay is not the disease appearing later, i