PDF: TUBEROUS SCLEROSIS - A Case Report with Oral Manifestation

Tuberous sclerosis (TS) complex is an autosomal dominant disease with largely variable clinical manifestations.

It belongs to the neurocutaneous disorders, or phacomatoses, such as neurofibromatosis, von Hippel-Lindau syndrome, and Sturge-Weber syndrome (Scully, 1977). The first to describe the disease was von Recklinghausen, in 1862, in a newborn child with multiple cardiac and brain tumors. However, the term TS was coined years later by Bourneville and Pringle who described the association of renal and cerebral lesions, but without cutaneous manifestations (Crino & Henske, 1999). In 1908, Vogt linked seizures, mental retardation and adenoma sebaceum (facial angiofibromas), known as the Vogt triad. This triad is only seen in a third of the cases (Morse, 1998). The incidence of TS ranges from 1/10,000 to 1/500,000, depending on the study (Scully, 1981; Gomez, 1988).

Two tumor suppressing genes, TSC1 and TSC2, are though to be responsible for the pathogenesis of TS and are located on chromosomes 9q and 16p, respectively (Fryer et al., 1987). About two thirds of cases are new mutations in patients with no family history of this disorder. An identifiable mutation has not yet been found to explain the remainder of cases (Kwiatkowska et al., 1998). The disease has greater than 95% penetrance. However, phenotypic differences have been identified between TSC1 and TSC2 mutations (Kwiatkowska et al.).

The incomplete expression of the disease or "forme fruste", first described by Schuster in 1914, is responsible for many undiagnosed cases of this disorder. Due to these complexities, the diagnosis of TS is currently based on clinical findings and genetic testing is indicated for research studies only.

The diagnostic criteria for TS were developed by Gomez using both clinical and radiographic evidence. They are categorized into major and minor criteria and any of them are diagnostic features by themselves. The definitive diagnosis is reached whenever patients present 2 major or 1 major plus 2 minor findings on examination. The organs most commonly affected are the brain, skin, kidneys, heart, eyes, and lung.

The most frequent neurological manifestations are the cortical tubers, found in more than 80% of patients with TS, leading to seizure disorders and mental retardation (Lendvay & Marshall, 2003). Up to 98% of patients with TS have seizures, 75% within the first year of life. However, patients may have cortical tubers without seizures and mental retardation (Lendvay & Marshall).

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