Unexpected death of a 12 year old boy with monosomy 1p36.

Monosomy 1p36 may result in a clinically recognizable chromosomal microdeletion syndrome. We report the unexpected death of a 12 year old boy with mildly dysmorphic facial features, short stature at 138 cm (3rd centile), moderate mental retardation and a history of seizures, obesity, transient muscle weakness of the right arm and leg and episodes of transient atonic hemiparesis of the right side of the body. Despite the relatively few congenital anomalies and normal karyotype, the 1p36 deletion was suspected on clinical grounds and was demonstrated by fluorescent in situ hybridisation (FISH). Two months after diagnosis and following a short history of a mild upper airway infection, high fever and severe diarrhea, the patient had a massive circulatory shock and asystolia, resulting in deep coma, brain edema, apallic syndrome and death. To our knowledge there has been no previous report of episodes of transient unilateral muscle weakness and atonic hemiparesis, circulatory shock and sudden death associated with monosomy 1p36.