Mutations in the LPIN1 gene (# 605518) are associated with lipodystrophy, hypertriglyceridemia
and insulin resistance. Beyond that mutations in the LPIN1 gene were reported to cause
rhabdomyolysis (Zeharia et al., 2008). Recently LPIN1 gene mutations were described
as a major cause for recurrent myoglobinuria and rhabdomyolysis in childhood (Michot
et al., 2010). Deficiency of the gene product lipin-1 leads to impaired synthesis
of phospholipids, accumulation of detrimental intermediates in cells and defective
cell membranes. Rhabdomyolysis shows often an recurrent course of disease and a high
mortality. Episodes were triggered predominantly by febrile illnesses, fastening or
strenuous exercise. Further repression of lipin-1 is induced by inflammatory cytokines
(TNF-α, IL-1β). Between episodes of rhabdomyolysis physical examination and laboratory
tests are often in normal limits.
We report a 33-month old boy who died four weeks after an acute bout of myositis beginning
during a febrile airway infection. The autopsy demonstrated an acute congestive heart
failure as the cause of death. A dilated cardiomyopathy with partial thinning of the
cardiac muscle indicated a pre-existing damage. Furthermore a minor preductal coarctation
of the aorta, and signs for a peripheral neuropathy were found. All examined muscle
tissues showed myopathic damages. After his death the results of the genetic testing
detected compound heterozygous LPIN1-mutations. Cause of death in this case is likely a combination of cardiac failure
with respiratory exhaustion as a result of the decompensated cardiomyopathy. This
might be triggered by the foregoing bout of rhabdomyolysis during a febrile infection.
Furthermore cardiac arrhythmia as cause of death can't be excluded as neuropathic
changes has been found on autopsy.
As conclusion, we recommend in patients with LPIN1 gene mutations preventive measures
like avoiding prolonged fasting periods as well as strenuous exercises. Cardiac examinations
should be performed routinely also in asymptomatic siblings.