Griscelli syndrome and electroencephalography pattern.

Dr. Paulo B.N. Liberalesso – Rua Benjamin Constant 90 / 73 80060-050 Curitiba PR Brasil. E-mail: [email protected] In 1978 in France, Claude Griscelli and Michel Prunieras reported the cases of two girls who presented with silver gray hair, several episodes of fever, hepatosplenomegaly and pancytopenia. The combination of pigment dilution and recurrent infectious episodes raised the diagnosis of Chediak-Higashi syndrome. However, since giant granules were not seen in granulocytes, there were differences in light and electron microscopic examination of skin and hair and there were defects in cellular and humoral immunity, the authors proposed a new syndrome. Since then, a little over than 60 cases of Griscelli syndrome (GS) have been reported in the medical literature in association with primary neurologic manifestations, with immunologic abnormalities or with silvery gray hair and hypopigmented skin as the only abnormality. The physiopathology of GS is based on a limited transport of melanin taking to a melanossoma deposition in the melanocytes. Many of these cases were found in multiple siblings and/or consanguineous parents, suggesting an autossomal recessive inheritance. In 1997, Pastural et al. found a homozygous mutation of the gene encoding myosin VA protein (MYO5A) in a Turkish girl with Griscelli syndrome. In 2000, the same author presented evidence indicating the existence of a second locus associated with GS in the 15q21 region, which is located less than 7,3cm from the MYO5A gene, the RAB27A gene. Currently, GS is classified into 3 types based on the genetic and molecular features. GS 1 is described as silvery gray hair, severe psychomotor delay and is related to MYO5A gene. GS 2 represents patients with silvery gray hair, immunologic abnormalities and variable neurologic defects and is related to RAB27A gene. Finally, GS 3 presents as hypopigmentation in the hair and skin without another findings and is related to a mutation in the 2q37.3 chromossome. The diagnosis is frequently made between 4 months and 7 years of age, with a 6-week-old patient being the youngest case reported. The main syndromes that should be considered in the differential diagnosis are Chediak-Higashi and Elejalde syndrome. This differentiation can be made through microscopic hair analysis and skin biopsy, and by the presence or absent of abnormalities in the granulocytes. This case report was approved by the ethics committee of Pequeno Principe Hospital and parental written informed consent was obtained for publication.