A late-onset case of neutral lipid storage disease with myopathy, dropped head syndrome, and peripheral nerve involvement

Neutral lipid storage disease with myopathy (NLSDM) is a rare autosomal recessive disorder of neutral lipid metabolism. Clinical manifestations include progressive skeletal myopathy, cardiomyopathy, and liver dysfunction. Clinical severity is variable and additional symptoms may include diabetes mellitus, chronic pancreatitis, hypothyroidism, neurosensory hearing loss, and short stature. We report a 79-year-old man with progressive proximal arm weakness, lipid storage myopathy, dropped head syndrome, and peripheral nervous system involvement. He harboured a novel homozygous missense mutation, c.570A>C (p.S191R) in the patatin-like phospholipase domain containing 2 (PNPLA2) gene, confirming the diagnosis of NLSDM. The S191R mutation causes late-onset NLSDM without cardiac dysfunction. The previously unreported association with dropped head syndrome expands the clinical spectrum of NLSDM.