Tuberous sclerosis: immunohistochemistry expression of tuberin and hamartin in a 31-week gestational fetus.
Tuberous sclerosis complex (TSC) is a common autosomal dominant disorder in which affected patients develop a wide variety of benign and malignant tumors. We report here on a 31-week gestational age fetus with pathological features of TSC. Developmental expression of hamartin and tuberin in various tissues was studied using immunohistochemistry. There was loss of expression of hamartin in the tuber and weak expression of the tuberin. Both hamartin and tuberin were expressed in bronchial epithelial cells, cardiac muscles, renal collecting tubules, and neural tissues. The rhabdomyomas stained negatively for tuberin and hamartin. Two genetic loci are responsible for TSC-TSCI and TSC2. The TSC1 gene on chromosome 9 encodes a protein termed hamartin that lacks sequence similarity to any known proteins, whereas the TSC2 gene on chromosome 16 codes for a protein termed tuberin. These results indicate that tuberin and hamartin may play a critical role in development and thus provide a framework for understanding the developmental and hamartomatous manifestations of tuberous sclerosis.
Vinaitheerthan
M
M
Department of Pathology, University of South Florida School of Medicine, Tampa General Hospital, P.O. Box 1289, Tampa, FL 33601, USA. mvinaith@hsc.usf.edu
Wei
J
J
Mizuguchi
M
M
Greco
A
A
Barness
E Gilbert
EG
D001921:Brain / Q000378:metabolism / Q000473:pathology; D005260:Female; D005333:Fetus; D006338:Heart Neoplasms / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D011247:Pregnancy; D012097:Repressor Proteins / Q000096:biosynthesis*; D012207:Rhabdomyoma / Q000378:metabolism / Q000473:pathology; D014402:Tuberous Sclerosis / Q000378:metabolism* / Q000473:pathology; D000077004:Tuberous Sclerosis Complex 1 Protein; D000077005:Tuberous Sclerosis Complex 2 Protein; D025521:Tumor Suppressor Proteins / Q000096:biosynthesis*
D012097:Repressor Proteins; C000624650:TSC1 protein, human; C000624653:TSC2 protein, human; D000077004:Tuberous Sclerosis Complex 1 Protein; D000077005:Tuberous Sclerosis Complex 2 Protein; D025521:Tumor Suppressor Proteins