Niemann-Pick type C (NPC) disease is a neurometabolic disorder that causes premature death and rapidly progressive neurological disability. It affects 1 in 100,000 live births and has a heterogeneous presentation.
Case: We present a 3-month-old boy with significant failure to thrive that was initially misdiagnosed as acquired CMV infection. He had concomitant RSV bronchitis with acute respiratory failure.
Long follow-up, family history and genetic testing led to the diagnosis of Niemann-Pick type C disease.
Conclusion: Long-term follow-up is essential for the diagnosis of rare diseases.