title: Distinct clinical characteristics of tuberous sclerosis complex patients with no mutation identified.
abstract: Tuberous Sclerosis Complex (TSC) is a multi-system disorder that is highly variable in its clinical presentation. Current molecular diagnostic methods permit identification of mutations in either TSC1 or TSC2 in 75-85% of TSC patients. Here we examine the clinical characteristics of those TSC patients who have no mutation identified (NMI). A retrospective review of our patient population that had comprehensive testing for mutations in TSC1/TSC2 identified 23/157 (15%) that were NMI. NMI patients had a lower incidence of brain findings on imaging studies, neurological features, and renal findings than those with TSC2 mutations. In contrast, NMI patients had a lower incidence of seizures than TSC patients with TSC1 mutations, but had a higher incidence of both renal angiomyolipomas and pulmonary lymphangioleiomyomatosis. This distinct constellation of findings suggest that NMI patients may have a unique molecular pathogenesis, different from that seen in TSC patients with the usual mutations in TSC1 and TSC2. We suggest that the mechanisms of disease in these patients include both mosaicism for a TSC2 mutation, and unusual non-coding region mutations in TSC2.
authors.affiliation: Carol and James Herscot Center for Tuberous Sclerosis Complex, Department of Neurology, Massachusetts General Hospital, 175 Cambridge Street, Boston, MA 02114, USA. scamposano@partners.org
authors.forename: S E
authors.initials: SE
authors.lastname: Camposano
authors.forename: E
authors.initials: E
authors.lastname: Greenberg
authors.forename: D J
authors.initials: DJ
authors.lastname: Kwiatkowski
authors.forename: E A
authors.initials: EA
authors.lastname: Thiele
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014402:Tuberous Sclerosis / Q000175:diagnosis / Q000235:genetics* / Q000473:pathology / Q000503:physiopathology*; D000077004:Tuberous Sclerosis Complex 1 Protein; D000077005:Tuberous Sclerosis Complex 2 Protein; D025521:Tumor Suppressor Proteins / Q000235:genetics; D055815:Young Adult
chemical_list: C000624650:TSC1 protein, human; C000624653:TSC2 protein, human; D000077004:Tuberous Sclerosis Complex 1 Protein; D000077005:Tuberous Sclerosis Complex 2 Protein; D025521:Tumor Suppressor Proteins