Abstract for presentation at 11th International Congress of Human Genetics

A Case report of Zimmermann-Laband syndrome caused by a Chromosomal Insertion: ins(12;8)(p11.2;q11.2q24.3)

  • C Hoogendijk, Registrar, Department of Oral and Maxillofacial Surgery, University of Pretoria, South Africa
  • Engela Honey, Senior Lecturer, Department of Genetics, University of Pretoria, South Africa
  • J Marx, Senior Technical Assistant, Department of Anatomy, University of Pretoria, South Africa
  • E Pretorius, Associate Professor, Department of Anatomy, University of Pretoria, South Africa
  • A Christianson, Professor, Department of Human Genetics, National Health Laboratory Services and the University of the Witwatersrand, Johannes, South Africa

    • Zimmermann-Laband Syndrome (ZLS) is a very rare genetic disorder inherited as an autosomal dominant trait with de novo mutations described in sporadic cases. The syndrome was first recognised and described in 1928 and subsequently 34 cases have been reported. The syndrome is characterized by the presence of 3 major clinical phenomena constituting gingival fibromatosis or hypertrophy, abnormalities of either the terminal phalanx or the nails of the hands or feet, as well as enlargement of the soft tissues of the face. Numerous variable clinical findings have also been described. Apart from a study by Stefanova and co-workers, who described the syndrome in a mother and daughter with a balanced reciprocal translocation, all the patients described in previous case studies, presented with a normal karyotype.
    A 14-year-old black male patient was referred to the Oral and Dental Hospital, Pretoria, South Africa for the treatment of hypertrophic gingiva. Other features consisting with the diagnosis of ZLS was present. He also had medullary expansion of the cranial vault as well as intracerebral calcifications reported on the CT scan that has never been described before in patients presenting with ZLS. Histology and Transmission Electron Microscopy (TEM) analysis of gingival tissue confirmed the diagnosis as gingival fibromatosis.
    Cytogenetic analysis of high resolution G-banded chromosomes revealed an insertion of the long-arm segment between bands 8q11.2 and 8q23.3 of one homologue of chromosome 8 into the short arm of one homologue of chromosome 12 at band p11.2. With the breakpoint in the translocation in the previously reported two patients corresponding with the breakpoint in the insertion in our patient at 8q24.3 we propose that the gene must lie in that location. Further studies are being undertaken to localize the gene.

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