Ruptured intracranial aneurysm in an adolescent with Alport's syndrome--a new expression of type IV collagenopathy: case report.

BACKGROUND: Aneurysmal subarachnoid hemorrhage is uncommon in the pediatric and adolescent age groups. Collagenopathies, particularly of collagen type III and IV, have been recognized in the pathogenesis of intracranial (i.c.) aneurysms in recent studies of cerebrovascular immunoreactivity and the molecular architecture of the walls of cerebral blood vessels. Alport's syndrome is a genetic disease characterized by imperfect synthesis of type IV collagen leading to sensorineural hearing loss and hematuria. The hematuria results from an abnormal synthesis of the type IV collagen of the glomerular basement membrane.

CASE DESCRIPTION: After a motor vehicle accident, this 14-year-old male driver presented with diffuse subarachnoid hemorrhage confirmed by computerized tomography. Subsequent cerebral angiography revealed a left carotid artery bifurcation aneurysm. A retrospective review of the patient's history disclosed renal biopsy-proven hereditary Alport's syndrome. The patient underwent left pterional craniotomy and clipping of the aneurysm, which had clearly ruptured.

CONCLUSIONS: The authors present the first clinical observation of a ruptured cerebral aneurysm in an adolescent male with Alport's syndrome. In this case the type IV collagenopathy of Alport's syndrome may have contributed to the genesis of this adolescent's aneurysm. Intracranial aneurysms may be more common in the population of collagenopathies than previously suspected and non-invasive screening may be appropriate.