Sequencing CHST3 in children with osteochondrodysplasia associated congenital dislocation

• Grant number: 12/08687-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2012
• End date: December 31, 2012
• Field of knowledge: Biological Sciences - Genetics - Human and Medical Genetics
• Principal Investigator: Denise Pontes Cavalcanti
• Grantee: Rafaela Mendonça Baggio
• Host Institution: Faculdade de Ciências Médicas (FCM). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

The skeletal dysplasias or osteochondrodysplasias (OCD) are a group of diseases affecting both, the growth and development of the skeletal system, and are characterized by great clinical and genetic heterogeneity. Despite the great heterogeneity and complexity of these conditions the diagnosis begins with the history, clinical examination, and radiography, however, for differential diagnosis, the molecular study is fundamental nowadays. According to the current classification of OCD, some dysplasias are characterized by multiple joint dislocations. One of these dysplasias, recently named Spondyloepiphyseal dysplasia with congenital joint dislocations, CHST3 type (SED-CHST3 type) has been included in the group of sulfation disorders. This dysplasia corresponds to the formerly named recessive Larsen syndrome. Mutations in CHST3 have been observed in a spectrum of phenotypes including humor-spinal dysostosis (HSD) spondyloepiphyseal dysplasia Omani type (SED-Omani type), besides the SED-CHST3 type. The CHST3 has three exons, but only exons 2 and 3 are transcribed. This gene spans over 20 kb and is located on 10q22.1.Mutations in CHST3 have been described in only 24 patients, most of them in exon 3, in the sulfotransferase domain. The identification of a family with a child showing clinical and radiological features compatible with the SED-CHST3 type prompted us to investigate this gene in this family and look for other suspected cases to test this CHST3. For this study, genomic DNA will be extracted using standard protocols. The coding region of CHST3 will be amplified from primers previously designed and sequencing analysis will be performed in both directions with the BigDye Terminator using an ABI sequencer (Applied Biosystems). The finding of mutations in the propositus will be complemented by the study of the parents. Other possible investigations will depend on the found results.(AU)