Forensic Considerations in Cases of Myotonic Dystrophy at Autopsy.

Myotonic dystrophy (DM) is a chronic, slowly progressive, autosomal-dominant disorder with delayed muscle relaxation after contraction, distal skeletal muscle weakness, and atrophy. It has a reduced life expectancy due predominantly to respiratory failure or sudden cardiac death. The mortality rate is approximately 7.3 times greater than the general population with a mean age at death of 53 years. Degeneration of the cardiac conduction system causes atrioventricular block, arrhythmias, and ventricular failure. A case of sudden death in a 44-year-old woman with DM type 1 is reported to demonstrate an alternative lethal mechanism. At autopsy, there was extensive infiltration of skeletal muscles with adipose tissue. The heart was structurally normal. A deep venous thrombosis of the right calf was identified with a large saddle pulmonary thromboembolus and bilateral peripheral thromboemboli. DM1-related thrombosis had most likely occurred because of the decedent's impaired mobility, possible hypercoagulable state, and serum changes from muscle necrosis.

Lethal mechanisms in gastric volvulus.

A 55-year-old wheelchair-bound woman with severe cerebral palsy was found at autopsy to have marked distention of the stomach due to a volvulus. The stomach was viable, and filled with air and fluid and had pushed the left dome of the diaphragm upwards causing marked compression of the left lung with a mediastinal shift to the right (including the heart). There was no evidence of gastric perforation, ischaemic necrosis or peritonitis. Removal of the organ block revealed marked kyphoscoliosis. Histology confirmed the viability of the stomach and biochemistry showed no dehydration. Death in cases of acute gastric volvulus usually occurs because of compromise of the gastric blood supply resulting in ischaemic necrosis with distention from swallowed air and fluid resulting in perforation with lethal peritonitis. Hypovolaemic shock may also occur. However, the current case demonstrates an alternative lethal mechanism, that of respiratory compromise due to marked thoracic organ compression.

Neonatal Limb Amputation-An Unusual Form of Postmortem Canine Predation.

Cases of postmortem canine predation often involve elderly recluses and their dogs. The face, head, and genitalia are targeted. Two unusual cases of postmortem canine predation of abandoned newborns are described to demonstrate an unusual alternative pattern of mutilation related to the small size of the decedents, marked decomposition, and canine scavenging behavior. Both bodies were abandoned/concealed soon after birth and were subsequently disturbed by dogs. Both were markedly decomposed with absent arms. Other injuries included skin and soft tissue defects of the torsos, with loss of distal portions of the right foot and the left lower leg in one case. No interstitial hemorrhage was observed in any of the exposed soft tissue wounds. There were no significant head or neck injuries. These cases show that patterns of postmortem canine predation will vary depending on the age, physical characteristics, degree of decomposition, and location of decedents.

Obesity, Body Mass Index, and Homicide.

The body mass indexes (BMIs) of 100 randomly selected homicide cases from the files of Forensic Science SA were compared to the Australian and South Australian populations. There were 70 males and 30 females (M:F = 2.3:1; age range 18-84 years; mean 42.3 years). There was a substantially lower proportion of obese individuals in the homicide population compared to the general Australian and South Australian populations (19% [vs.] 27.9% and 30%, respectively). A second group of 144 randomly selected autopsy cases where the BMI was ≥40 kg/m2 was analyzed. There were 77 males and 67 females (M:F = 1.2:1; age range 23-78 years; mean 46.7 years). The majority of deaths were natural (N = 108), with no homicides. A negative association between obesity and homicide has, therefore, been demonstrated. Reasons for the lower numbers of obese/morbidly obese individuals among homicide victims are unclear, but may include physical protection afforded by fat padding from sharp force injuries, and relative sociodemographic isolation.