Tuberous sclerosis in a 19-week fetus: Immunohistochemical and molecular study of hamartin and tuberin

Jianjun Wei, Peng Li, Luis Chiriboga, Masashi Mizuguchi, Herman Yee, Douglas C. Miller, M. Alba Greco*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

12 Scopus citations


Tuberous sclerosis complex (TSC) is a genetically heterogeneous disease caused by mutations of TSC1 or TSC2 genes. It involves multiple organ systems resulting in mild to lethal hamartoma formation due to gene mutation in the germ line and loss of heterozygosity (LOH) in somatic cells. Hamartin (TSC1) and tuberin (TSC2) are expressed broadly. However, little is known about tissue susceptibility to hamartomas when equal or similar amounts of TSC gene expression are present. In this study, we present a 19-week gestational age fetus with pathological features of TSC, which was confirmed by finding LOH of TSC2 in a cardiac rhabdomyoma. Developmental expression of hamartin and tuberin in the TSC fetus, an age-matched non-TSC fetus, and a 26-week gestational age non-TSC fetus were analyzed by immunohistochemistry. We found that in addition to the differential expression of the TSC genes in some normal tissues compared with that in the TSC-affected fetus, the cellular localization and distribution of hamartin and tuberin were dramatically different in different tissues. In general, hamartin and tuberin are mainly expressed in epithelial cells, myocytes, and neural tissues. By comparing the incidence of the hamartomas in early childhood and gene expression in tissues, it appears that tissues with co-expression of hamartin and tuberin are prone to a higher incidence of hamartomas than those expressing only one protein, or two proteins but in different patterns of cellular localization.

Original languageEnglish (US)
Pages (from-to)448-464
Number of pages17
JournalPediatric and Developmental Pathology
Issue number5
StatePublished - Sep 1 2002


  • Fetus
  • Hamartin
  • Immunohistochemistry
  • Loss of herozygosity
  • Tuberin
  • Tuberous sclerosis complex

ASJC Scopus subject areas

  • Pediatrics, Perinatology, and Child Health
  • Pathology and Forensic Medicine


Dive into the research topics of 'Tuberous sclerosis in a 19-week fetus: Immunohistochemical and molecular study of hamartin and tuberin'. Together they form a unique fingerprint.

Cite this